Genotypic and Allelic Distribution of the CD36 rs1761667 Polymorphism in High-Level Moroccan Athletes: A Pilot Study

Previous studies have shown that variations in the CD36 gene may affect phenotypes associated with fat metabolism as the CD36 protein facilitates the transport of fatty acids to the mitochondria for oxidation. However, no previous study has tested whether variations in the CD36 gene are associated with sports performance. We investigated the genotypic and allelic distribution of the single-nucleotide polymorphism (SNP) rs1761667 in the CD36 gene in elite Moroccan athletes (cyclists and hockey players) in comparison with healthy non-athletes of the same ethnic origin. Forty-three Moroccan elite male athletes (nineteen cyclists and twenty-four field hockey players) belonging to the national teams of their respective sports (athlete group) were compared to twenty-eight healthy, active, male university students (control group). Genotyping of the CD36 rs1761667 (G>A) SNP was performed via polymerase chain reaction (PCR) and Sanger sequencing. A chi-square (χ2) test was used to assess the Hardy-Weinberg equilibrium (HWE) and to compare allele and genotype frequencies in the "athlete" and "control" groups. The genotypic distribution of the CD36 rs1761667 polymorphism was similar in elite athletes (AA: 23.81, AG: 59.52, and GG: 16.67%) and controls (AA: 19.23, AG: 69.23, and GG: 11.54%; χ2 = 0.67, p = 0.71). However, the genotypic distribution of the CD36 rs1761667 polymorphism was different between cyclists (AA: 0.00, AG: 72.22, and GG: 27.78%) and hockey players (AA: 41.67, AG: 50.00, and GG: 8.33%; χ2 = 10.69, p = 0.004). Specifically, the frequency of the AA genotype was significantly lower in cyclists than in hockey players (p = 0.02). In terms of allele frequency, a significant difference was found between cyclists versus field hockey players (χ2 = 7.72, p = 0.005). Additionally, there was a predominance of the recessive model in cyclists over field hockey players (OR: 0.00, 95% CI: 0.00-0.35, p = 0.002). Our study shows a significant difference between cyclists and field hockey players in terms of the genotypic and allelic frequency of the SNP rs1761667 of the CD36 gene. This divergence suggests a probable association between genetic variations in the CD36 gene and the type of sport in elite Moroccan athletes.

An epidermal growth factor receptor compound mutation of L858R with S768I in advanced non-small-cell lung cancer: a case report

BACKGROUND

In the current treatment landscape for non-small cell lung cancers, epidermal growth factor receptor-tyrosine kinase inhibitors have emerged as a well-established treatment option for patients with advanced or metastatic disease. This is particularly true for those with commonly occurring epidermal growth factor receptor mutations. However, the therapeutic efficacy of these agents for so-called rare epidermal growth factor receptor mutations, and in particular those characterized by a high degree of complexity, such as double mutations, remains a subject of clinical uncertainty.

CASE PRESENTATION

In this context, we present the case of a 64-year-old man of Moroccan descent, a lifelong non-smoker, diagnosed with metastatic non-small cell lung cancer characterized by a complex epidermal growth factor receptor mutation encompassing L858R and S768I. The patient subsequently underwent afatinib-based treatment, showing notable clinical results. These included a remarkable overall survival of 51 months, with a median progression-free survival of more than 39 months.

CONCLUSIONS

This case report is a compelling testimony to the evolving therapeutic landscape of non-small cell lung cancers, providing valuable insight into the potential therapeutic efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors in the realm of rare and complex epidermal growth factor receptor mutations.

Impact of Deletion on Angelman Syndrome Phenotype Variability: Phenotype-Genotype Correlation in 97 Patients with Motor Developmental Delay

Angelman syndrome (AS) is a rare neurodevelopmental disorder due to genetic defects involving chromosome 15, known by intellectual disability, cognitive and behavioral disorders, ataxia, delayed motor development, and seizures. This study highlights the clinical spectrum and molecular research to establish the genotype-phenotype correlation in the pediatric Moroccan population. Methylation-specific-polymerase chain reaction (MS-PCR) is a primordial technique not only to identify the genetic mechanism of AS but also to characterize the different molecular classes induced in the appearance of the clinical symptoms. Patients with positive methylation profile were additionally studied by fluorescent in situ hybridization. Sequencing analysis of the UBE3A gene was performed for patients with negative MS-PCR. We used Fisher's test to assess differences in the distribution of features frequencies among the deletional and the nondeletional group. Statistical analysis was performed using R project. We identified from 97 patients diagnosed with AS, 14 (2.06%) had a classical AS phenotype, while 70 (84.5%) patients displayed a subset of consistent and frequent criteria. Development delay was shown severe in 63% and moderate in 37%. Nineteen out of 97 of them had MS-PCR positive in which 17 (89.47%) had 15q11-q13 deletion. Deletion patients presented a higher incidence of epileptic seizures ( p  = 0.04), ataxia ( p  = 0.0008), and abnormal electroencephalogram (EEG) profile ( p  = 0.003). We further found out a frameshift deletion located at exon 9 of the UBE3A gene discovered in a 5 years old patient. We report in this study the genotype-phenotype correlation using different molecular testing. Correlation analysis did not reveal any statistical differences in phenotypic dissimilarity between deletion and nondeletion groups for most clinical features, except the correlation was highly significant in the abnormal EEG. According to our findings, we recommend offering MS-PCR analysis to all patients with severe intellectual disability, developmental delay, speech impairment, happy demeanor, and hypopigmentation.

Identification of novel and de novo variant in the SCN1A gene confirms Dravet syndrome in Moroccan child: a case report

Dravet syndrome is a severe form of epilepsy characterised by recurrent seizures and cognitive impairment. It is mainly caused by variant in the SCN1A gene in 90% of cases, which codes for the α subunit of the voltage-gated sodium channel. In this study, we present one suspected case of Dravet syndrome in Moroccan child that underwent exome analysis and were confirmed by Sanger sequencing. The variant was identified in the SCN1A gene, and is a new variant that has never been described in the literature. The variant was found de nova in our case, indicating that it was not inherited from the parents. The variant, SCN1A c.965-2A>G p.(?), is located at the splice site and results in an unknown modification of the protein. This variant is considered pathogenic on the basis of previous studies. These results contribute to our knowledge of the SCN1A gene mutations associated with Dravet syndrome and underline the importance of genetic analysis in the diagnosis and confirmation of this disorder. Further studies are needed to better understand the functional consequences of this variant and its implications for therapeutic strategies in Dravet syndrome.

Unraveling the Diversity of GJB2 Mutations in Nonsyndromic Hearing Loss: A Comprehensive Study in the Moroccan Population

INTRODUCTION

Despite the high genetic heterogeneity of hearing loss, mutations in the GJB2 gene are a major cause of autosomal recessive nonsyndromic hearing loss (NSHL) worldwide. However, the mutation profile of GJB2 in NSHL is under-investigated in Morocco, especially among simplex cases. This study aimed to identify the spectrum and frequency of GJB2 mutations in the Moroccan population among simplex and multiplex families with NSHL.

METHODS

Moroccan families with NSHL were selected according to well-defined criteria. Selected families were screened for GJB2 gene variants using direct sequencing of the entire coding region of GJB2.

RESULTS

A total of 145 affected individuals from 115 families with NSHL were included in this study (49 simplex, 66 multiplex). Mutations in the GJB2 gene were noted in 28.69% of the families (33/115), of which 75.75% were multiplex families and 24.24% were simplex. In total, seven different mutations were detected: c.35delG(p.G12fs), c.551G>A(p.R184Q), c.139G>T(p.E47X), c.109G>A(p.V37I), c.167delT(p.L56fs), c.617A>G(p.N206S), c.94C>T(p.R32C). The last three mutations have not previously been reported in Morocco. The most common GJB2 mutation was c.35delG (21.73%), followed by p.V37I (2.60%) and p.E47X (1.73%).

CONCLUSIONS

Our study confirms a high prevalence of GJB2 variants in the Moroccan population, particularly the c.35delG mutation. Additionally, we have identified previously unreported or rarely reported mutations, revealing a greater diversity of GJB2 mutations. These findings emphasize the importance of comprehensive screening beyond the 35delG mutation for patients with NSHL, regardless of their family history. Integrating this approach into clinical care will enhance diagnosis and management of hearing loss in the Moroccan population.

The burden of cystic fibrosis in North Africa

Background: Over 200 pathogenic variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with cystic fibrosis (CF)-the most prevalent autosomal recessive disease globally, the p.Phe508del variant being the most commonly observed. Main text: Recent epidemiological studies suggest a higher global prevalence of CF than previously thought. Nevertheless, comprehensive CF data remains extremely scarce among African populations, contributing to a significant information gap within the African healthcare system. Consequently, the underestimation of CF among children from African populations is likely. The goal of this article is to review the pathogenesis of CF and its prevalence in the countries of North Africa. Conclusion: The prevalence of CF in North African countries is likely underestimated due to the complexity of the disease and the lack of a timely, proper clinical and genetic investigation that allows the early identification of CF patients and thus facilitates therapeutic recommendations. Therefore, specific genetic and epidemiological studies on African individuals showing CF symptoms should be conducted to enhance the diagnostic yield of CF in Africa.

RAS Mutations Predict Recurrence-Free Survival and Recurrence Patterns in Colon Cancer: A Unicenter Study in Morocco

PURPOSE

To date, only a few studies have investigated the role of molecular alterations in cancer recurrence. This exploratory study aimed to evaluate the impact of molecular alterations on the time and site of recurrence in patients with stage I-IV CRC and to identify the risk factors predicting recurrence-free survival in colon cancer.

METHODS

A total of 270 patients were retrospectively included. We assessed the full RAS status using Sanger and pyrosequencing. MSI status was determined by immunohistochemical analysis. Molecular alterations were correlated with recurrence timing (early or late), recurrence patterns, and recurrence-free survival. Statistical analysis was performed using the Kaplan-Meier method and the log-rank test.

RESULTS

Of the 270 patients, 85 (31%) experienced recurrence, among whom 53% had mutant full RAS status, 48% had KRAS mutations, and 31.4% had KRAS p. G12V mutation subtype. Compared with those with late recurrence, patients with early recurrence were significantly older (P = 0.02) and more likely to have poorly differentiated tumors, a higher rate of positive lymph nodes, KRAS mutations, and especially KRAS p. G12V mutation variant. RAS mutation status, KRAS mutations, and rare mutations are more common in patients with lung cancer recurrence. Multivariate logistic regression analysis revealed that differentiation, perineural invasion, full RAS mutation status, and KRAS codon 13 mutations were independent factors for recurrence-free survival in colon cancer.

CONCLUSION

In this cohort, the timing and patterns of recurrence appeared to be associated with the patient's molecular profile. KRAS codon 12 mutations were the worst predictors of recurrence-free survival at all stages in our population.

Genetic characterization of Schuurs-Hoeijmakers syndrome in a moroccan individual with heterozygote PACS1 mutation

BACKGROUND

Schuurs-Hoeijmakers syndrome, an autosomal dominant neurodevelopmental genetic disorder, is a rare cause of intellectual disability (ID) affecting approximately 1 to 3% of all over the world. Only 87 cases have been recorded to date, and oddly enough, the majority of them share the same mutation (c.607 C > T; p.R203W).

CASE PRESENTATION

This study presents the first reported case in Morocco of a 12-year-old female patient with PACS1 syndrome, identified during a cohort study of 24 patients with intellectual disability. The syndrome is caused by a de novo mutation of the PACS1 gene, located on chromosome 11, resulting in a single amino acid modification on the PACS1 protein. The abnormal protein disrupts cellular transport processes, leading to intellectual developmental delay, facial dysmorphia, and congenital anomalies.

METHODS AND RESULTS

Exome sequencing was employed to identify the genetic mutation, and Sanger sequencing validated the presence of the recurrent mutation c.607 C > T (p.Arg203Trp) in the PACS1 gene. The mutation was found to be heterozygous and de novo, suggesting that it was not inherited from the patient's parents. Classification based on the American College of Medical Genetics and Genomics (ACMG) criteria confirmed its pathogenicity, with supporting evidence from bioinformatics analysis. The rarity of this variant in population databases further supports its pathogenic nature.

CONCLUSION

This study expands our understanding of Schuurs-Hoeijmakers syndrome, a disorder with limited reported cases globally. The genetic heterogeneity of the disorder is highlighted, with the recurrent mutation being the most common pathogenic variant. Functional studies indicate the crucial role of PACS1 in craniofacial development and neurodevelopmental processes, with potential implications for autism spectrum disorders (ASD). Comprehensive genetic analyses are essential for accurate diagnosis and understanding the underlying causes of intellectual disabilities. Further research is warranted to unravel the mechanisms and potential therapeutic targets associated with PACS1-related neurodevelopmental disorders.

A homozygous missense variant in the PLCB4 gene causes severe phenotype of auriculocondylar syndrome type 2

Auriculocondylar syndrome (ARCND) is a rare craniofacial birth defect characterized by malformations in the mandible and external ear (Question Mark Ear). Genetically, three distinct subtypes of ARCND (ARCND1, ARCND2, and ARCND3) have been identified. ARCND2 is linked to pathogenic variants in the PLCB4 gene (phospholipase C β4). PLCB4 is a key effector of the EDN1-EDNRA pathway involved in craniofacial development via the induction, migration, and maintenance of neural crest cells. ARCND2 is typically inherited in an autosomal dominant pattern, with recessive inheritance pattern being rare. In this study, we report the first homozygous missense variant (NM_000933.4: c.2050G>A: p.(Gly684Arg)) in the PLCB4 gene causing ARCND in a 3-year-old patient with a severe clinical phenotype of the syndrome. The patient presented with typical craniofacial ARCND features, in addition to intestinal transit defect, macropenis, and hearing loss. These findings further delineate the phenotypic spectrum of ARCND associated with autosomal recessive PLCB4 loss of function variants. Notably, our results provide further evidence that these variants can result in a more severe and diverse manifestations of the syndrome. Clinicians should consider the rare features of this condition for better management of patients.

Influence of CYP450 Enzymes and ABCB1 Polymorphisms on Clopidogrel Response in Moroccan Patients with Acute Coronary Syndromes

Introduction

Clopidogrel is an antiplatelet prodrug primarily prescribed to prevent or treat acute coronary syndrome (ACS) or acute ischemic stroke (IS), polymorphisms of genes encoding cytochrome P-450 (CYP) and P-glycoprotein transporter, could affect the efficiency of clopidogrel absorption and biotransformation, especially during the first critical hours following its administration.

Methods

The present study was designed to investigate the potential association of clopidogrel responsiveness and 14 polymorphisms in the genes encoding the CYPs (CYP2C9, 2C19, 3A4, 3A5, 1A2, and 2B6), the ATP binding cassette subfamily B member 1 (ABCB1). Platelet aggregation activity was measured after 8h of 300mg clopidogrel administration for fifty-five ACS patients.

Results

There was no significant association between polymorphism of the studied CYPs and clopidogrel responsiveness (P>0.05). The frequency of the ABCB1 3435 T allele in clopidogrel non-responders was higher (78.9%) compared to responders (52.8%), but this difference was not significant (P=0.057). Demographic characteristics, comorbidities, concomitant treatments were not associated with clopidogrel response.

Discussion

There was no effect of the studied genetic variations and demographic factors on the platelet activity of clopidogrel in Moroccan ACS patients.

Novel APOE Mutation in a Moroccan Subject Suffering from Alzheimer Disease: A Case Study and Exploration of Pathogenic Implication

Alzheimer disease (AD) is a major public health concern worldwide. It is a severe neurodegenerative disease that primarily affects the elderly and causes significant brain cell death. According to the most complete scientific research, the APOE gene, which encodes the APOE protein, maybe the key to identifying the likely cause of delayed AD. The development of plaques and tangles, as well as increased amyloid (amyloid-β) levels and deposition, have been linked to APOE4. Pathogenic mutations in this gene can impact how beta-amyloid deposits and how they are cleared from the body. In this study, we report a novel pathogenic mutation, Arg160Leu, in APOE that was identified in a Moroccan patient. The magnetic resonance imaging of this 67-year-old woman revealed hippocampal shrinkage, and the results of her cognition testing revealed that she is suffering from severe AD. The current study may increase awareness of the genetic risk factors for AD caused by APOE4 mutations.

New Biomarkers and Treatment Advances in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a specific subtype of breast cancer lacking hormone receptor expression and HER2 gene amplification. TNBC represents a heterogeneous subtype of breast cancer, characterized by poor prognosis, high invasiveness, high metastatic potential, and a tendency to relapse. In this review, the specific molecular subtypes and pathological aspects of triple-negative breast cancer are illustrated, with particular attention to the biomarker characteristics of TNBC, namely: regulators of cell proliferation and migration and angiogenesis, apoptosis-regulating proteins, regulators of DNA damage response, immune checkpoints, and epigenetic modifications. This paper also focuses on omics approaches to exploring TNBC, such as genomics to identify cancer-specific mutations, epigenomics to identify altered epigenetic landscapes in cancer cells, and transcriptomics to explore differential mRNA and protein expression. Moreover, updated neoadjuvant treatments for TNBC are also mentioned, underlining the role of immunotherapy and novel and targeted agents in the treatment of TNBC.

Rare and Atypical Case of Turner Syndrome With Three Cell Lines

Turner's syndrome is a rare complex genetic disease characterized by gonadal dysgenesis and sexual chromosomal abnormalities. Half of the patients affected are monosomic, for the X chromosome, and for the remaining patients, a variety of chromosomal abnormalities have been reported. Only a small percentage (3%-4%) of people with Turner syndrome have triple X cell line mosaicism (47, XXX). It has been reported that patients 45, X/47, XXX have normal intelligence, a higher rate of spontaneous menstruation, an increased number of pregnancies, and a lower frequency of short stature (60%) compared to patients 45, X. In this work, we will present a rare and atypical case of a patient who presents a rare chromosomal mosaicism, with three chromosomal lineages, contrasting with a typical clinical picture of Turner syndrome.

Heterogeneous distribution of EGFR mutation in NSCLC: Case report

Background

We herein report the case of a patient with advanced lung adenocarcinoma who presented a heterogeneous distribution of EGFR mutation.

Case report

A 74-year-old Moroccan male former smoker was diagnosed with advanced lung adenocarcinoma, harboring S768I exon 20 substitution mutation confirmed by Real Time PCR and Pyrosequencing, but not detected by direct sequencing despite 70% of tumor cells. The present report describes a case of minor histologic intratumoral heterogeneity with heterogeneous distribution of EGFR mutation.

Conclusion

Both sensitivity and specificity of molecular methods can provide evidence of intratumoral heterogeneity, which may explain the mismatch between the validation of oncology biomarkers and predicting therapeutic response to targeted therapy.

The Diagnosis and Genetic Mechanisms of Prader-Willi Syndrome: Findings From a Moroccan Population Study

Background Prader-Willi syndrome (PWS) is a complex genetic disorder caused by a deficit in gene expression on the paternal inherited chromosome 15q11.2-q13. It affects various aspects of growth and development, including feeding, cognitive function, and behavior. Early diagnosis and management of PWS can significantly improve outcomes for patients and their families. Methods In this study, we analyzed a group of 29 clinically diagnosed patients suspected of PWS. All patients were referred to the medical genetics and onco-genetics service for genetic consultation and molecular analysis. We used DNA methylation analysis and fluorescence in situ hybridization (FISH) to confirm the diagnosis and identify the underlying genetic mechanisms. Results Our analysis showed that five out of seven patients (71.43%) with a positive methylation-specific PCR (MSP) had chromosomal deletion by FISH and presented major clinical signs summarized by morbid obesity in 65.21% of cases and neonatal hypotonia in 42.85% of cases. This finding indicates that paternal 15q11-q13 deletion is the most common genetic mechanism involved in PWS. Conclusion The results of this study highlight the importance of early diagnosis and molecular analysis in the management of Prader-Willi syndrome. Our findings contribute to a better understanding of the genotype-phenotype correlation in the Moroccan population and provide families with a rigorous molecular diagnosis, relevant genetic counseling, and multidisciplinary support. Further research is needed to explore the underlying mechanisms of PWS and develop effective interventions to improve outcomes for affected individuals.

A Mosaic PIK3CA Mutation in a Moroccan Female: Exploring the Diagnostic Challenges of PIK3CA-Related Overgrowth Spectrum

The PIK3CA-related overgrowth spectrum (PROS) encompasses a group of rare disorders characterized by the overgrowth of various body parts, driven by mutations in the PIK3CA gene. This study presents a case of a Moroccan female patient with PROS, demonstrating a phenotype associated with genetic mosaicism in the PIK3CA gene. A multidisciplinary approach, involving clinical examination, radiological assessment, and genetic and bioinformatic analyses, was employed for diagnosis and management. Next-generation sequencing and Sanger sequencing identified a rare variant, c.353G>A, in exon 3 of the PIK3CA gene, not detected in leukocyte DNA but confirmed in tissue biopsy samples. The comprehensive analysis of this case furthers our understanding of PROS and highlights the importance of a multidisciplinary approach to the diagnosis and management of this rare disorder.

Clinical Evidence of Circulating Tumor DNA Application in Aggressive Breast Cancer

Breast cancer is clinically and biologically heterogeneous and is classified into different subtypes according to the molecular landscape of the tumor. Triple-negative breast cancer is a subtype associated with higher tumor aggressiveness, poor prognosis, and poor response to treatment. In metastatic breast cancer, approximately 6% to 10% of new breast cancer cases are initially staged IV (de novo metastatic disease). The number of metastatic recurrences is estimated to be 20-30% of all existing breast tumor cases, whereby the need to develop specific genetic markers to improve the prognosis of patients suffering from these deadly forms of breast cancer. As an alternative, liquid biopsy methods can minutely identify the molecular architecture of breast cancer, including aggressive forms, which provides new perspectives for more precise diagnosis and more effective therapeutics. This review aimed to summarize the current clinical evidence for the application of circulating tumor DNA in managing breast cancer by detailing the increased usefulness of this biomarker as a diagnostic, prognostic, monitoring, and surveillance marker for breast cancer.

Clinical and molecular characterization of Xeroderma pigmentosum in Moroccan population: a case series of 40 patients

Background

Xeroderma pigmentosum (XP) is a rare autosomal recessive skin disorder characterized by hyperpigmentation, premature skin aging, ocular and cutaneous photosensitivity with increased risk of skin tumors. XP is caused by mutations in DNA repair genes that protect cells from UV-induced DNA damage. The current study aims to investigate, on clinical and genetic basis, Moroccan XP patients. We explored by direct sequencing the involvement of the prevalent XPA and XPC genes mutations: nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643 1644delTG or p.Val548Ala fsX25), respectively, in 40 index cases from 37 unrelated families in Moroccan population.

Results

Early skin and ocular manifestations were detected with high rate of malignancy. Cutaneous lesions progressed to malignant skin tumor in 70% of cases. Ocular tumors were also observed in 11 patients including BCC in eight cases, SCC in three cases and melanoma in four cases. Among the 40 patients, there were 20 homozygous cases for the 2 bp deletion in the XPC gene and 9 homozygous cases carrying the nonsense XPA mutation.

Conclusion

These findings obtained in the present study revealed that the XPC gene mutation (c.1643 1644delTG, p.Val548AlafsX25) is the major cause of Xeroderma pigmentosum in our population. The c.682C>T (p.Arg228X) mutation is relatively associated with moderate phenotype in XP group A Moroccan families. This result will also contribute to improving the molecular diagnosis of XP disease and will have a significant impact on improving the care of Moroccan patients and their relatives.

Review of prostate cancer genomic studies in Africa

Prostate cancer (PCa) is the second most commonly diagnosed in men worldwide and one of the most frequent cancers in men in Africa. The heterogeneity of this cancer fosters the need to identify potential genetic risk factors/biomarkers. Omics variations may significantly contribute to early diagnosis and personalized treatment. However, there are few genomic studies of this disease in African populations. This review sheds light on the status of genomics research on PCa in Africa and outlines the common variants identified thus far. The allele frequencies of the most significant SNPs in Afro-native, Afro-descendants, and European populations were compared. We advocate how these few but promising data will aid in understanding, better diagnosing, and precisely treating this cancer and the need for further collaborative research on the genomics of PCa in the African continent.

Initiation of the pharmacogenetics of capecitabine in Morocco

Introduction:

The pharmacogenetics of anticancer drugs is of paramount importance in minimizing their side effects and increasin their efficacy. When applied to capecitabine, the result is that variation in patient responses has been largely linked to different genetic polymorphisms of dihydropyrimidine dehydrogenase (DPD) and this variation explains in many cases the onset of toxicity of this medication in patients. Failure of this enzyme is known to be responsible for a high incidence of serious or even fatal side effects. In this study conducted on Moroccan patients under treatment with capecitabine at usual doses at the Fez University Hospital, the first in Africa and Morocco, we are looking for the presence of four variants of DPD gene (DPYD): T486A on exon 5 (rs666523971), c.1679T> G (p.I560S; rs55886062; allele DPYD * 13) on exon 13, c.1905 + 1G> A (IVS14 + 1G> A; rs3918290; allele DPYD * 2A) on the splice site near exon 14 and the c.2846A> T mutation (p.D949V; rs67376798) on exon 22. We will therefore seek to establish the cause-and-effect relationship between this toxicity and the presence of these variants in his patients, which will allow us to avoid the dangerous prescription of capecitabine in patients carrying these polymorphisms.

Methods:

This is a prospective study which is carried out at the Laboratory of Medical Genetics of the CHU Hassan II Fez and spread over a period of 3 years. Patient recruitment was carried out from the oncology department of CHU Hassan II-Fès. All recruited patients are treated with capecitabine A total of 64 patients were tested. Blood samples (5 ml) were obtained from each one of them after their consent and DNA was extracted. The study of these four polymorphisms was carried out by PCR sequencing.

Results and Discussion:

We have studied 64 patients taking capecitabine. Their median age was 50 years and the mean age of 50,79 years with extremes of 25 and 78 years. The sex ratio F / M was 0,60. Different levels of toxicity have been developed in patients ranging from simple vomiting to IV degree hand and foot syndrome and second degree neuropathy involving total discontinuation of treatment. These mutations were not found in the patients. Thus it would be interesting to enlarge the sample size, to look for these polymorphisms and others on other exons of the DPYD gene and to try to understand the cause of this increased incidence of capecitabine toxicity in the Moroccan population.

Conclusion:

Capecitabine-based chemotherapy caused adverse effects with varying levels in its patients. The SNPs on the DPYD gene sought were not found in this Moroccan sample. It is desirable to screen more patients and to search for other SNPs to understand the toxicity of capecitabine in relation to the DPYD gene. This will make it possible to adjust the dosage of this drug, increase its effectiveness and minimize its toxicity.

Prognostic Impact of Tumor Budding on Moroccan Colon Cancer Patients

BACKGROUND

Tumor budding is now emerging as one of the robust and promising histological factors that play an important role in colon cancer. In this study, we aimed to investigate the association between tumor budding and tumor clinicopathological factors, tumor molecular signature, and patient survival for the first time in a Moroccan population.

METHODS

We collected data of 100 patients operated from colon adenocarcinoma. Tumor budding was assessed on HES slides, according to the International Tumor Budding Consensus Conference 2016 recommendations. The expression of MMR proteins was performed by immunohistochemistry. KRAS and NRAS mutations testing was performed by Sanger sequencing and pyrosequencing.

RESULTS

High tumor budding grade (BUD 3) was found to be significantly associated with adverse clinicopathological features including older age (P=0.03), presence of perineural invasion (P=0.02), presence of vascular invasion (P=0.05), distant metastases (P < 0.001), advanced TNM stage (P=0.001), the occurrence of relapse (P=0.04), and the high number of deceased cases (P=0.02). Interestingly, we found that tumors with high-grade tumor budding were more likely to be microsatellite stable (MSS) (P=0.005) and harbor more KRAS mutations (P=0.02). Tumors with high-grade tumor budding were strongly associated with KRAS G12D mutation (P=0.007). In all stages, high tumor budding was correlated with poorer overall survival (P=0.04) and decreased relapse-free survival with a difference close to significance ((P=0.09). We concluded that high tumor budding was strongly associated with unfavorable clinicopathological features and special molecular biomarkers and effectively affects the overall survival of CC patients.

CONCLUSIONS

Based on these findings and the ITBCC group recommendations, tumor budding should be taken into account along with other clinicopathologic factors in the risk assessment of colorectal cancer.

Dietary Fat Intake and KRAS Mutations in Colorectal Cancer in a Moroccan Population

Epidemiologic data support an association between diet and mutations in the Kirsten-ras (KRAS) gene involved in colorectal cancer (CRC) development. This study aimed to explore the associations between fat intake and KRAS mutations in codons 12 and 13 in cases of CRC in the Moroccan population. A multicenter case-series study nested in a large-scale Moroccan CRC case-control study was conducted. Among all CRC cases recruited, 151 specimens were available for the DNA mutation analysis. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (Cis) for KRAS mutation status according to the fat intake variables. A KRAS mutation was detected in the CRC tumor of 34.4% of the patients among whom 65.4% had a single mutation at codon 12 and 34.6% had a single mutation at codon 13. Compared to low levels of consumption, a positive association was observed between high polyunsaturated fatty acids (PUFA) consumption (>16.9 g/day) and prevalence of KRAS mutations (OR = 2.15, 95% CI = 1.01-4.59). No statistically significant associations were observed for total fat, monounsaturated fatty acids, saturated fatty acids and KRAS mutations. The results of this study suggest that PUFA may be relevant in the etiology of CRC, possibly through the generation of G > A transitions at the KRAS oncogene. Further studies are needed to verify and explain this finding.

Correlation of Epidermal Growth Factor Receptor Mutation With Major Histologic Subtype of Lung Adenocarcinoma According to IASLC/ATS/ERS Classification

OBJECTIVE

Our prospective study aims to define the correlation of EGFR(epidermal growth factor receptor) mutations with major histological subtypes of lung adenocarcinoma from resected and non-resected specimens, according to the WHO 2015 classification, in Moroccan North East Population.

METHODS

Epidermal growth factor receptor mutations of 150 primary lung adenocarcinoma were performed using Real-Time PCR or SANGER sequencing. SPSS 21 was used to assess the relationship between histological subtypes of lung adenocarcinoma and EGFR mutation status.

RESULTS

25 mutations were detected in the series of 150 lung adenocarcinomas, most of which were found in cases with papillary, acinar, patterns than without these patterns and more frequently occurred in the cases without solid pattern than with this pattern. A significant correlation was observed between EGFR mutation and acinar (P = 0,024), papillary pattern (P = 0,003) and, negative association with a solid pattern (P < 0,001). In females, EGFR mutations were significantly correlated with the acinar pattern (P = 0,02), whereas in males with the papillary pattern (P = 0,01). Association between the histologic component and exon 19 deletions and exon 21 mutations were also evaluated and, we found a significant correlation between the papillary major pattern with exon 19 mutations (P = 0,004) and, ex21 with the acinar component (P = 0,03).

CONCLUSION

An analysis of resected and non-resected lung ADC specimens in 150 Moroccan Northeast patients, revealed that acinar and papillary patterns may predict the presence of a mutation in the EGFR gene. While the solid major pattern may indicate a low mutation rate of the EGFR gene.

Screening of NKX2.5 gene in Moroccan Tetralogy of Fallot (TOF) patients: worldwide mutation rate comparisons show a significant association between R25C variant and TOF phenotype

Background

Tetralogy of Fallot is the most prevalent cyanotic congenital heart disease, occurring in 1/3 600 live births. This disorder comprises ventricular septal defect, right ventricular outflow obstruction, over-riding aorta, and right ventricular hypertrophy. The present study aims to reveal the spectrum of Nk2 homeobox 5 (NKX2-5) variants identified in a Moroccan non-syndromic tetralogy of Fallot cohort and to compare mutation rate with different studies from all over the world. Thirty-one patients with non-syndromic tetralogy of Fallot were recruited in this cross-sectional study. DNAs were extracted, and coding regions of NKX2.5 were PCR-amplified and sequenced. The obtained sequences were analyzed using different bioinformatics tools. Statistical comparisons were carried out using the R software.

Results

R25C mutation was found in two patients, in association with the E21E variant. The latter variant was frequently observed in the population and seems to have a potential altering effect on the splicing process. The NKX2.5 mutation rate in our tetralogy of Fallot population is around 6.4%, and no significant difference was noticed in comparison with previous studies. At the same time, a comparison of R25C mutation rate between atrial septal defect and tetralogy of Fallot worldwide populations shows a particular association of R25C mutation with tetralogy of Fallot phenotype.

Conclusions

This study reveals a consistency between our NKX2.5 mutation rate and those of different tetralogy of Fallot populations around the world. Our findings suggest a possible combined effect of R25C mutation and E21E variant on the carriers and emphasize particularly the significant association of R25C mutation with tetralogy of Fallot, which highlights the importance of an anticipative screening for TOF phenotype among the carriers’ offspring at the perinatal period.

Absence of GATA4 Mutations in Moroccan Patients with Atrial Septal Defect (ASD) Provides Further Evidence of Limited Involvement of GATA4 in Major Congenital Heart Defects

Objective

Atrial septal defect (ASD) is one of the most common types of congenital heart disease (CHD). It is mainly caused by mutations of NK2 homeobox 5, GATA binding protein 4 (GATA4), and myosin heavy chain 6 in non-syndromic cases. This study aims to carry out, for the first time, the GATA4 mutation screening in a Moroccan population affected by ASD and compare the obtained mutation rate across populations.

Materials and Methods

A total of 33 patients were enrolled in this study. DNAs were extracted from peripheral blood samples, and we performed PCR-sequencing for GATA4 coding regions. Sequences were analyzed by sequence alignment and functional impact prediction tools. Mutation rate comparisons were performed by R software using the appropriate statistical tests.

Results

We detected 7 variants, but no pathogenic mutation was revealed, except for Asn352= that was assessed by human splicing finder algorithms to have a potential impairing effect on the splicing mechanism. Until proven by in vitro functional studies, the current pathogenic mutation rate in our cohort seems to be 0%. Statistical comparison with previous studies from all over the world shows no significant difference. Seemingly, comparison of previous GATA4 mutation rates among tetralogy of Fallot (TOF) populations shows no significant difference.

Conclusion

The low rates of GATA4 mutations observed throughout ASD and TOF international populations may suggest a limited causality of GATA4 mutations in the main CHDs, which further confirms the co-involvement of additional genetic and/or environmental factors in the manifestation of these phenotypes.

Associations between nutritional factors and KRAS mutations in colorectal cancer: a systematic review

BACKGROUND

Between 30 and 50% of colon tumors have mutations in the Kirsten-ras (KRAS) gene, which have a large nutritional attributable risk. Despite its high frequency in colorectal cancer (CRC), data to support specific associations between KRAS mutations in CRC and diet are sparse. Here, we conducted a systematic review to summarize the current epidemiological evidence on the association between various dietary factors and KRAS mutations.

METHODS

PubMed, Science Direct, and Cochrane databases were searched for relevant studies published until December 31, 2019, using inclusion and exclusion criteria in accordance with PRISMA guidelines. We analyzed the studies to find associations between nutritional factors and CRC tumors with KRAS mutations in humans.

RESULTS

We identified 28 relevant studies to include in this systematic review. In-depth analyses showed unclear associations between nutritional factors and KRAS mutations in CRC. Most epidemiological studies in the same nutrient or food often reported conflicting and/or inconclusive findings, whereas for some dietary factors, the results were homogeneous.

CONCLUSIONS

Further research using a more robust prospective cohort study is needed to lend more credence to the epidemiological associations found between KRAS mutations and dietary factors.

Molecular and environmental characterization of Noonan syndrome in Morocco reveals a significant association with consanguinity and advanced parental age

Background

Noonan syndrome (NS) is one of the most common RASopathies, with an autosomal dominant inheritance. This disorder is caused by a range of genes belonging to the RAS-MAP kinase (rat sarcoma viral oncogene homolog/mitogen-activated protein kinases) pathway, with PTPN11 (protein-tyrosine phosphatase, non-receptor type 11) being the most involved genetic factor.

The aim of this study is to report PTPN11 mutations found in a cohort of Moroccans with Noonan syndrome, compare the mutation rate with various studies, and statistically assess involvement of prominent risk factors in manifestation of this disorder.

Thirty-one NS patients were screened for PTPN11 mutations using PCR-Sanger sequencing method. Pathogenic effect prediction, for detected variants, was carried out using PROVEAN, MutationTaster2, and HSF programs. Statistical tests were performed with R software. Chi-square and Fisher’s exact tests were used in percentage comparisons, while Student’s test was used in average comparisons.

Results

We detected five pathogenic mutations, one synonymous variant with a potential altering effect on splicing function, and three novel intronic duplications. PTPN11 mutation rate in our cohort is around 16.13%. Comparison of this rate with the corresponding rates in various populations shows notably significant differences across continents.

Conclusions

Besides genetic factors, the present study suggests involvement of additional environmental factors. Statistical assessment of clinical data confirms particularly the association of NS manifestation with consanguinity and advanced paternal age, and suggests an eventual implication of advanced maternal age as well.

[Kallmann-de Morsier syndrome: about 3 cases]

Le syndrome de Kallmann-de Morsier (KS) est une maladie génétique du développement du système olfactif caractérisée par l'association d'un hypogonadisme hypogonadotrophique par déficit en gonadolibérine (GnRH) et d'une anosmie ou hyposmie. Le diagnostic se fait le plus souvent à l'adolescence devant une absence de puberté spontanée associée à un trouble de l'odorat, avec visualisation sur l'IRM hypothalamo-hypophysaire d'une hypoplasie voire une aplasie des bulbes et/ou des lobes olfactifs. Parfois, le diagnostic peut être évoqué dans la petite enfance devant l'association d'une cryptorchidie et d'un micropénis. Une mutation dans l'un de ses gènes connus n'est retrouvée que dans moins de 30% des cas et donc plusieurs autres gènes restent à découvrir. Grâce au traitement hormonal, la puberté se produit dans tous les cas, et la fertilité peut être obtenue dans la plupart des cas. Dans la présente étude, nous rapportons 3 cas de patients atteints de ce syndrome.

Williams-Beuren syndrome in diverse populations

Williams-Beuren syndrome (WBS) is a common microdeletion syndrome characterized by a 1.5Mb deletion in 7q11.23. The phenotype of WBS has been well described in populations of European descent with not as much attention given to other ethnicities. In this study, individuals with WBS from diverse populations were assessed clinically and by facial analysis technology. Clinical data and images from 137 individuals with WBS were found in 19 countries with an average age of 11 years and female gender of 45%. The most common clinical phenotype elements were periorbital fullness and intellectual disability which were present in greater than 90% of our cohort. Additionally, 75% or greater of all individuals with WBS had malar flattening, long philtrum, wide mouth, and small jaw. Using facial analysis technology, we compared 286 Asian, African, Caucasian, and Latin American individuals with WBS with 286 gender and age matched controls and found that the accuracy to discriminate between WBS and controls was 0.90 when the entire cohort was evaluated concurrently. The test accuracy of the facial recognition technology increased significantly when the cohort was analyzed by specific ethnic population (P-value < 0.001 for all comparisons), with accuracies for Caucasian, African, Asian, and Latin American groups of 0.92, 0.96, 0.92, and 0.93, respectively. In summary, we present consistent clinical findings from global populations with WBS and demonstrate how facial analysis technology can support clinicians in making accurate WBS diagnoses.

Molecular and presymptomatic analysis of a Moroccan Lynch syndrome family revealed a novel frameshift MLH1 germline mutation

Lynch syndrome (LS) is an autosomal dominant disorder characterized by an increased risk of extracolonic cancers and early age of onset. It is associated with germline mutations in the DNA mismatch repair (MMR) genes. We report a case of a patient with colorectal cancer referred to our medical genetics department for molecular analysis and genetic counseling. The proband is a 64-year-old woman diagnosed with a tumor of the cecum. Histopathological examination showed a moderately differentiated mucinous adenocarcinoma categorized by pT3 N0. Analysis of her pedigree revealed three siblings who had colon cancer, as well as one relative with brain cancer. Based on these findings, molecular genetic investigation was found to be necessary in order to identify the disease-causing mutation. Immunohistochemistry staining of MMR proteins was performed on the tumor sample of the index proband. Mutational analysis of the MLH1/MSH2 genes was carried out. Analysis was extended to the family members and the general population. This led to the identification of a heterozygous frameshift duplication in the MLH1 gene at position 910 (c.910dupG). Three siblings had inherited the mutation from their mother, two of whom were asymptomatic at the time of diagnosis. To the best of our knowledge, this is a novel pathogenic duplication that has not been reported in the databases and literature. The outcome of the present case suggests that this mutation was the primary cause of LS in the family.

GATA4 molecular screening and assessment of environmental risk factors in a Moroccan cohort with tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect (CHD) with an incidence of 1/3600 live births. This disorder was associated with mutations in the transcription factors involved in cardiogenesis, like Nk2 homeobox5 (NKX2-5), GATA binding protein4 (GATA4) and T-BOX1 (TBX1). GATA4 contributes particularly to heart looping and differentiation of the second heart field.

Objectives

The aim of this study was to screen a Moroccan cohort with tetralogy of Fallot for GATA4 mutations, and to assess environmental risk factors that could be involved in the occurrence of this disorder.

Methods

Thirty-one non-syndromic TOF patients, enrolled between 5^th April 2014 and 18^th June 2015, were screened for GATA4 mutations using direct sequencing of GATA4 coding exons. Statistical assessment of different risk factors, which is a retrospective study, was carried out using Chi-square and Fisher's exact tests.

Results

We identified seven exonic variants in nine patients (two missense and five synonymous variants); in addition of eight intronic variants. Assessment of environmental risk factors shows significant association of maternal passive smoking with TOF in the Moroccan population.

Conclusion

The present study allowed, for the first time, the molecular and environmental characterisation of Moroccan TOF population. Our findings emphasise particularly the strong association of passive smoking with the emergence of tetralogy of Fallot.

Helicobacter pylori CagA EPIYA-C motifs and gastric diseases in Moroccan patients

BACKGROUND

The pathogenicity of cagA-positive H. pylori strains is associated with the number and type of repeated sequences named EPIYA located in the C-terminal region of the CagA protein. The aim of this study is to determine the polymorphism of the H. pylori cagA 3' region circulating in Morocco and its association with different gastric pathologies.

METHODS

A total of 1353 consenting patients, were recruited in this study. The gastric biopsies performed during endoscopy were used for histological examination and for molecular characterization of H. pylori. The study of the type and number of "EPIYA" motif was identified by PCR directly on H. pylori positive biopsies.

RESULTS

Of all the biopsies, the infection rate was 61.1%. The cagA gene was amplified in 68.9% of the cases and the analysis of the 3' region of cagA showed the exclusive presence of the "Western CagA" type with a predominance of the EPIYA-ABC motif (71.4%). The number of EPIYA-C motif varies from 0 to 2. The multinomial analysis shows that the infection with strains of H. pylori having two EPIYA-C motifs is a factor that increases the risk of developing gastric cancer compared to gastritis cases with strains lacking this motif (OR = 11.64; CI: 3.34-45.15), whereas this risk is 6 fold higher in comparison with duodenal ulcer cases (OR = 6, CI: 1.29-27.76).

CONCLUSIONS

The results of this study suggest that the number of EPIYA-C motifs might be useful as a predictive marker of the infection evolution and will help in the identification of patients at high risk of developing gastric cancer.

The First Molecular Screening of MLH1 and MSH2 Genes in Moroccan Colorectal Cancer Patients Shows a Relatively High Mutational Prevalence

INTRODUCTION

Lynch syndrome (LS) is an autosomal dominant disorder characterized by early age of onset and increased risk of developing extracolonic tumors. Molecular diagnosis of LS requires identification of germline mutations in one of the Mismatch Repair (MMR) genes.

AIM

The objective of the study was to investigate the prevalence of MLH1/MSH2 mutation carriers among Moroccan patients with colorectal cancer (CRC) in a hospital-based cohort.

METHODS

In this study, 214 CRC patients from COLORECFez cohort were included. Patients whose tumors showed MMR deficiency (MMR-D) and wild-type BRAF were selected to undergo mutational analysis of the MLH1 and MSH2 genes using Sanger sequencing.

RESULTS

A total of 24 MMR-D tumors were identified (11.2%) among 214 CRC tested for MMR protein expression. The BRAF p.Val600Glu mutation was absent in all tumors deficient for MLH1 protein. Molecular screening showed germline MMR mutations (MLH1/MSH2) in four cases, two of which fulfilled Amsterdam criteria II and two met at least one of the revised Bethesda guidelines. The estimated frequency of MLH1/MSH2 mutations in Moroccan CRC patients was 1.87%.

CONCLUSIONS

The present study reports a relatively high incidence of MLH1/MSH2 (1.87%). These results confirm the contribution of MMR genes to CRC susceptibility in our population and provide evidence regarding the requirement of implementing a national screening program for LS in Morocco.

High frequency of the recurrent c.1310_1313delAAGA BRCA2 mutation in the North-East of Morocco and implication for hereditary breast-ovarian cancer prevention and control

Background

To date, a limited number of BRCA1/2 germline mutations have been reported in hereditary breast and/or ovarian cancer in the Moroccan population. Less than 20 different mutations of these two genes have been identified in Moroccan patients, and recently we reported a further BRCA2 mutation (c.1310_1313delAAGA; p.Lys437IlefsX22) in three unrelated patients, all from the North-East of the country. We aimed in this study to evaluate the frequency and geographic distribution of this BRCA2 frameshift mutation, in order to access its use as the first-line BRCA genetic testing strategy for Moroccan patients. We enrolled in this study 122 patients from different regions of Morocco, with suggestive inherited predisposition to breast and ovarian cancers. All subjects gave written informed consent to BRCA1/2 genetic testing. According to available resources of our lab and enrolled families, 51 patients were analyzed by the conventional individual exon-by-exon Sanger sequencing, 23 patients were able to benefit from a BRCA next generation sequencing and a target screening for exon 10 of BRCA2 gene was performed in 48 patients.

Results

Overall, and among the 122 patients analyzed for at least the exon 10 of the BRCA2 gene, the c.1310_1313delAAGA frameshift mutation was found in 14 patients. Genealogic investigation revealed that all carriers of this mutation shared the same geographic origin and were descendants of the North-East of Morocco.

Discussion

In this study, we highlighted that c.1310_1313delAAGA mutation of BRCA2 gene is recurrent with high frequency in patients from the North-East region of Morocco. Therefore, we propose to use, in public health strategies, the detection of this mutation as the first-line screening tests in patients with breast and ovarian cancer originated from this region.

Anémie de fanconi au CHU Hassan II Fès: à propos de 6 observations

L'anémie de Fanconi est une maladie récessive associée à une instabilité chromosomique, elle est marquée par une hétérogénéité phénotypique qui inclut une insuffisance médullaire, un syndrome malformatif variable, une prédisposition à développer des leucémies aiguës myéloïdes (LAM) et une hypersensibilité cellulaire aux agents pontant l'ADN. Le diagnostic est basé sur l'augmentation anormale du taux de cassures chromosomiques spontanées mais surtout, et de manière spécifique, sur une augmentation nette de ces cassures chromosomiques en présence d'agents alkylants bifonctionnels, ce qui est le cas pour nos six patients. Le conseil génétique rejoint celui des maladies autosomiques récessives. Nous rapportons nos premières observations au CHU Hassan II Fès, confirmées par la mise en évidence d'une grande instabilité chromosomique après culture sous Mitomycine C en comparaison avec un témoin normal. Le but de cet article est la mise à jour de nos connaissances sur la génétique de l'Anémie de Fanconi et à travers ces six observations nous illustrons le rôle de la cytogénétique dans le diagnostic et le conseil génétique pour une meilleure prise en charge aussi bien des enfants atteints que de leurs familles.

Noonan syndrome-causing genes: Molecular update and an assessment of the mutation rate

Noonan syndrome is a common autosomal dominant disorder characterized by short stature, congenital heart disease and facial dysmorphia with an incidence of 1/1000 to 2500 live births. Up to now, several genes have been proven to be involved in the disturbance of the transduction signal through the RAS-MAP Kinase pathway and the manifestation of Noonan syndrome. The first gene described was PTPN11, followed by SOS1, RAF1, KRAS, BRAF, NRAS, MAP2K1, and RIT1, and recently SOS2, LZTR1, and A2ML1, among others. Progressively, the physiopathology and molecular etiology of most signs of Noonan syndrome have been demonstrated, and inheritance patterns as well as genetic counseling have been established. In this review, we summarize the data concerning clinical features frequently observed in Noonan syndrome, and then, we describe the molecular etiology as well as the physiopathology of most Noonan syndrome-causing genes. In the second part of this review, we assess the mutational rate of Noonan syndrome-causing genes reported up to now in most screening studies. This review should give clinicians as well as geneticists a full view of the molecular aspects of Noonan syndrome and the authentic prevalence of the mutational events of its causing-genes. It will also facilitate laying the groundwork for future molecular diagnosis research, and the development of novel treatment strategies.

[Lynch syndrome: case report and review of the literature]

Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC) is the most common form of hereditary colorectal cancers. It increases cancer susceptibility, the risk of colorectal cancer in first-degree, endometrial cancer in women, and to a lesser extent, other cancers (ovarian, small bowel, stomach, urinary tract and hepatobiliary). Thus, the cumulative risk of developing colorectal cancer or endometrial cancer at the age of 80 years rises to 20 and 40% respectively. These cancers are characterized by a positive family history, their occurrence at an early age, and by the development of metachronous cancers in the same individual. This syndrome is transmitted in an autosomal dominant manner. The genes whose alteration is associated with the presence of an HNPCC belong to the family of DNA mismatch repair genes (DNA mismatch repair or MMR): MSH2, MLH1, and MSH6 are involved, in decreasing order of frequency, in 35%, 25% and 2% of cases respectively. Colonoscopic and gynecological monitoring is recommended for patients with a constitutional mutation in MSH2, MLH1 or Msh6 genes. We report one of the first moroccan case with Lynch syndrome whose constitutional mutation in the MLH1 gene was identified in a family member with colon cancer. In reply to the inquiry ofother healthy family members, a presymptomatic diagnosis was made allowing to formulate an appropriate monitoring strategy. Our study aims to highlight the role of oncogenetics in the management of patients with cancer and their families.

Human genome meeting 2016 : Houston, TX, USA. 28 February - 2 March 2016

O1 The metabolomics approach to autism: identification of biomarkers for early detection of autism spectrum disorder A. K. Srivastava, Y. Wang, R. Huang, C. Skinner, T. Thompson, L. Pollard, T. Wood, F. Luo, R. Stevenson O2 Phenome-wide association study for smoking- and drinking-associated genes in 26,394 American women with African, Asian, European, and Hispanic descents R. Polimanti, J. Gelernter O3 Effects of prenatal environment, genotype and DNA methylation on birth weight and subsequent postnatal outcomes: findings from GUSTO, an Asian birth cohort X. Lin, I. Y. Lim, Y. Wu, A. L. Teh, L. Chen, I. M. Aris, S. E. Soh, M. T. Tint, J. L. MacIsaac, F. Yap, K. Kwek, S. M. Saw, M. S. Kobor, M. J. Meaney, K. M. Godfrey, Y. S. Chong, J. D. Holbrook, Y. S. Lee, P. D. Gluckman, N. Karnani, GUSTO study group O4 High-throughput identification of specific qt interval modulating enhancers at the SCN5A locus A. Kapoor, D. Lee, A. Chakravarti O5 Identification of extracellular matrix components inducing cancer cell migration in the supernatant of cultivated mesenchymal stem cells C. Maercker, F. Graf, M. Boutros O6 Single cell allele specific expression (ASE) IN T21 and common trisomies: a novel approach to understand DOWN syndrome and other aneuploidies G. Stamoulis, F. Santoni, P. Makrythanasis, A. Letourneau, M. Guipponi, N. Panousis, M. Garieri, P. Ribaux, E. Falconnet, C. Borel, S. E. Antonarakis O7 Role of microRNA in LCL to IPSC reprogramming S. Kumar, J. Curran, J. Blangero O8 Multiple enhancer variants disrupt gene regulatory network in Hirschsprung disease S. Chatterjee, A. Kapoor, J. Akiyama, D. Auer, C. Berrios, L. Pennacchio, A. Chakravarti O9 Metabolomic profiling for the diagnosis of neurometabolic disorders T. R. Donti, G. Cappuccio, M. Miller, P. Atwal, A. Kennedy, A. Cardon, C. Bacino, L. Emrick, J. Hertecant, F. Baumer, B. Porter, M. Bainbridge, P. Bonnen, B. Graham, R. Sutton, Q. Sun, S. Elsea O10 A novel causal methylation network approach to Alzheimer’s disease Z. Hu, P. Wang, Y. Zhu, J. Zhao, M. Xiong, David A Bennett O11 A microRNA signature identifies subtypes of triple-negative breast cancer and reveals MIR-342-3P as regulator of a lactate metabolic pathway A. Hidalgo-Miranda, S. Romero-Cordoba, S. Rodriguez-Cuevas, R. Rebollar-Vega, E. Tagliabue, M. Iorio, E. D’Ippolito, S. Baroni O12 Transcriptome analysis identifies genes, enhancer RNAs and repetitive elements that are recurrently deregulated across multiple cancer types B. Kaczkowski, Y. Tanaka, H. Kawaji, A. Sandelin, R. Andersson, M. Itoh, T. Lassmann, the FANTOM5 consortium, Y. Hayashizaki, P. Carninci, A. R. R. Forrest O13 Elevated mutation and widespread loss of constraint at regulatory and architectural binding sites across 11 tumour types C. A. Semple O14 Exome sequencing provides evidence of pathogenicity for genes implicated in colorectal cancer E. A. Rosenthal, B. Shirts, L. Amendola, C. Gallego, M. Horike-Pyne, A. Burt, P. Robertson, P. Beyers, C. Nefcy, D. Veenstra, F. Hisama, R. Bennett, M. Dorschner, D. Nickerson, J. Smith, K. Patterson, D. Crosslin, R. Nassir, N. Zubair, T. Harrison, U. Peters, G. Jarvik, NHLBI GO Exome Sequencing Project O15 The tandem duplicator phenotype as a distinct genomic configuration in cancer F. Menghi, K. Inaki, X. Woo, P. Kumar, K. Grzeda, A. Malhotra, H. Kim, D. Ucar, P. Shreckengast, K. Karuturi, J. Keck, J. Chuang, E. T. Liu O16 Modeling genetic interactions associated with molecular subtypes of breast cancer B. Ji, A. Tyler, G. Ananda, G. Carter O17 Recurrent somatic mutation in the MYC associated factor X in brain tumors H. Nikbakht, M. Montagne, M. Zeinieh, A. Harutyunyan, M. Mcconechy, N. Jabado, P. Lavigne, J. Majewski O18 Predictive biomarkers to metastatic pancreatic cancer treatment J. B. Goldstein, M. Overman, G. Varadhachary, R. Shroff, R. Wolff, M. Javle, A. Futreal, D. Fogelman O19 DDIT4 gene expression as a prognostic marker in several malignant tumors L. Bravo, W. Fajardo, H. Gomez, C. Castaneda, C. Rolfo, J. A. Pinto O20 Spatial organization of the genome and genomic alterations in human cancers K. C. Akdemir, L. Chin, A. Futreal, ICGC PCAWG Structural Alterations Group O21 Landscape of targeted therapies in solid tumors S. Patterson, C. Statz, S. Mockus O22 Genomic analysis reveals novel drivers and progression pathways in skin basal cell carcinoma S. N. Nikolaev, X. I. Bonilla, L. Parmentier, B. King, F. Bezrukov, G. Kaya, V. Zoete, V. Seplyarskiy, H. Sharpe, T. McKee, A. Letourneau, P. Ribaux, K. Popadin, N. Basset-Seguin, R. Ben Chaabene, F. Santoni, M. Andrianova, M. Guipponi, M. Garieri, C. Verdan, K. Grosdemange, O. Sumara, M. Eilers, I. Aifantis, O. Michielin, F. de Sauvage, S. Antonarakis O23 Identification of differential biomarkers of hepatocellular carcinoma and cholangiocarcinoma via transcriptome microarray meta-analysis S. Likhitrattanapisal O24 Clinical validity and actionability of multigene tests for hereditary cancers in a large multi-center study S. Lincoln, A. Kurian, A. Desmond, S. Yang, Y. Kobayashi, J. Ford, L. Ellisen O25 Correlation with tumor ploidy status is essential for correct determination of genome-wide copy number changes by SNP array T. L. Peters, K. R. Alvarez, E. F. Hollingsworth, D. H. Lopez-Terrada O26 Nanochannel based next-generation mapping for interrogation of clinically relevant structural variation A. Hastie, Z. Dzakula, A. W. Pang, E. T. Lam, T. Anantharaman, M. Saghbini, H. Cao, BioNano Genomics O27 Mutation spectrum in a pulmonary arterial hypertension (PAH) cohort and identification of associated truncating mutations in TBX4 C. Gonzaga-Jauregui, L. Ma, A. King, E. Berman Rosenzweig, U. Krishnan, J. G. Reid, J. D. Overton, F. Dewey, W. K. Chung O28 NORTH CAROLINA macular dystrophy (MCDR1): mutations found affecting PRDM13 K. Small, A. DeLuca, F. Cremers, R. A. Lewis, V. Puech, B. Bakall, R. Silva-Garcia, K. Rohrschneider, M. Leys, F. S. Shaya, E. Stone O29 PhenoDB and genematcher, solving unsolved whole exome sequencing data N. L. Sobreira, F. Schiettecatte, H. Ling, E. Pugh, D. Witmer, K. Hetrick, P. Zhang, K. Doheny, D. Valle, A. Hamosh O30 Baylor-Johns Hopkins Center for Mendelian genomics: a four year review S. N. Jhangiani, Z. Coban Akdemir, M. N. Bainbridge, W. Charng, W. Wiszniewski, T. Gambin, E. Karaca, Y. Bayram, M. K. Eldomery, J. Posey, H. Doddapaneni, J. Hu, V. R. Sutton, D. M. Muzny, E. A. Boerwinkle, D. Valle, J. R. Lupski, R. A. Gibbs O31 Using read overlap assembly to accurately identify structural genetic differences in an ashkenazi jewish trio S. Shekar, W. Salerno, A. English, A. Mangubat, J. Bruestle O32 Legal interoperability: a sine qua non for international data sharing A. Thorogood, B. M. Knoppers, Global Alliance for Genomics and Health - Regulatory and Ethics Working Group O33 High throughput screening platform of competent sineups: that can enhance translation activities of therapeutic target H. Takahashi, K. R. Nitta, A. Kozhuharova, A. M. Suzuki, H. Sharma, D. Cotella, C. Santoro, S. Zucchelli, S. Gustincich, P. Carninci O34 The undiagnosed diseases network international (UDNI): clinical and laboratory research to meet patient needs J. J. Mulvihill, G. Baynam, W. Gahl, S. C. Groft, K. Kosaki, P. Lasko, B. Melegh, D. Taruscio O36 Performance of computational algorithms in pathogenicity predictions for activating variants in oncogenes versus loss of function mutations in tumor suppressor genes R. Ghosh, S. Plon O37 Identification and electronic health record incorporation of clinically actionable pharmacogenomic variants using prospective targeted sequencing S. Scherer, X. Qin, R. Sanghvi, K. Walker, T. Chiang, D. Muzny, L. Wang, J. Black, E. Boerwinkle, R. Weinshilboum, R. Gibbs O38 Melanoma reprogramming state correlates with response to CTLA-4 blockade in metastatic melanoma T. Karpinets, T. Calderone, K. Wani, X. Yu, C. Creasy, C. Haymaker, M. Forget, V. Nanda, J. Roszik, J. Wargo, L. Haydu, X. Song, A. Lazar, J. Gershenwald, M. Davies, C. Bernatchez, J. Zhang, A. Futreal, S. Woodman O39 Data-driven refinement of complex disease classification from integration of heterogeneous functional genomics data in GeneWeaver E. J. Chesler, T. Reynolds, J. A. Bubier, C. Phillips, M. A. Langston, E. J. Baker O40 A general statistic framework for genome-based disease risk prediction M. Xiong, L. Ma, N. Lin, C. Amos O41 Integrative large-scale causal network analysis of imaging and genomic data and its application in schizophrenia studies N. Lin, P. Wang, Y. Zhu, J. Zhao, V. Calhoun, M. Xiong O42 Big data and NGS data analysis: the cloud to the rescue O. Dobretsberger, M. Egger, F. Leimgruber O43 Cpipe: a convergent clinical exome pipeline specialised for targeted sequencing S. Sadedin, A. Oshlack, Melbourne Genomics Health Alliance O44 A Bayesian classification of biomedical images using feature extraction from deep neural networks implemented on lung cancer data V. A. A. Antonio, N. Ono, Clark Kendrick C. Go O45 MAV-SEQ: an interactive platform for the Management, Analysis, and Visualization of sequence data Z. Ahmed, M. Bolisetty, S. Zeeshan, E. Anguiano, D. Ucar O47 Allele specific enhancer in EPAS1 intronic regions may contribute to high altitude adaptation of Tibetans C. Zeng, J. Shao O48 Nanochannel based next-generation mapping for structural variation detection and comparison in trios and populations H. Cao, A. Hastie, A. W. Pang, E. T. Lam, T. Liang, K. Pham, M. Saghbini, Z. Dzakula O49 Archaic introgression in indigenous populations of Malaysia revealed by whole genome sequencing Y. Chee-Wei, L. Dongsheng, W. Lai-Ping, D. Lian, R. O. Twee Hee, Y. Yunus, F. Aghakhanian, S. S. Mokhtar, C. V. Lok-Yung, J. Bhak, M. Phipps, X. Shuhua, T. Yik-Ying, V. Kumar, H. Boon-Peng O50 Breast and ovarian cancer prevention: is it time for population-based mutation screening of high risk genes? I. Campbell, M.-A. Young, P. James, Lifepool O53 Comprehensive coverage from low DNA input using novel NGS library preparation methods for WGS and WGBS C. Schumacher, S. Sandhu, T. Harkins, V. Makarov O54 Methods for large scale construction of robust PCR-free libraries for sequencing on Illumina HiSeqX platform H. DoddapaneniR. Glenn, Z. Momin, B. Dilrukshi, H. Chao, Q. Meng, B. Gudenkauf, R. Kshitij, J. Jayaseelan, C. Nessner, S. Lee, K. Blankenberg, L. Lewis, J. Hu, Y. Han, H. Dinh, S. Jireh, K. Walker, E. Boerwinkle, D. Muzny, R. Gibbs O55 Rapid capture methods for clinical sequencing J. Hu, K. Walker, C. Buhay, X. Liu, Q. Wang, R. Sanghvi, H. Doddapaneni, Y. Ding, N. Veeraraghavan, Y. Yang, E. Boerwinkle, A. L. Beaudet, C. M. Eng, D. M. Muzny, R. A. Gibbs O56 A diploid personal human genome model for better genomes from diverse sequence data K. C. C. Worley, Y. Liu, D. S. T. Hughes, S. C. Murali, R. A. Harris, A. C. English, X. Qin, O. A. Hampton, P. Larsen, C. Beck, Y. Han, M. Wang, H. Doddapaneni, C. L. Kovar, W. J. Salerno, A. Yoder, S. Richards, J. Rogers, J. R. Lupski, D. M. Muzny, R. A. Gibbs O57 Development of PacBio long range capture for detection of pathogenic structural variants Q. Meng, M. Bainbridge, M. Wang, H. Doddapaneni, Y. Han, D. Muzny, R. Gibbs O58 Rhesus macaques exhibit more non-synonymous variation but greater impact of purifying selection than humans R. A. Harris, M. Raveenedran, C. Xue, M. Dahdouli, L. Cox, G. Fan, B. Ferguson, J. Hovarth, Z. Johnson, S. Kanthaswamy, M. Kubisch, M. Platt, D. Smith, E. Vallender, R. Wiseman, X. Liu, J. Below, D. Muzny, R. Gibbs, F. Yu, J. Rogers O59 Assessing RNA structure disruption induced by single-nucleotide variation J. Lin, Y. Zhang, Z. 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Abduljaleel P13 Digital expression profiling of Purkinje neurons and dendrites in different subcellular compartments A. Kratz, P. Beguin, S. Poulain, M. Kaneko, C. Takahiko, A. Matsunaga, S. Kato, A. M. Suzuki, N. Bertin, T. Lassmann, R. Vigot, P. Carninci, C. Plessy, T. Launey P14 The evolution of imperfection and imperfection of evolution: the functional and functionless fractions of the human genome D. Graur P16 Species-independent identification of known and novel recurrent genomic entities in multiple cancer patients J. Friis-Nielsen, J. M. Izarzugaza, S. Brunak P18 Discovery of active gene modules which are densely conserved across multiple cancer types reveal their prognostic power and mutually exclusive mutation patterns B. S. Soibam P19 Whole exome sequencing of dysplastic leukoplakia tissue indicates sequential accumulation of somatic mutations from oral precancer to cancer D. Das, N. Biswas, S. Das, S. Sarkar, A. Maitra, C. Panda, P. Majumder P21 Epigenetic mechanisms of carcinogensis by hereditary breast cancer genes J. J. Gruber, N. Jaeger, M. Snyder P22 RNA direct: a novel RNA enrichment strategy applied to transcripts associated with solid tumors K. Patel, S. Bowman, T. Davis, D. Kraushaar, A. Emerman, S. Russello, N. Henig, C. Hendrickson P23 RNA sequencing identifies gene mutations for neuroblastoma K. Zhang P24 Participation of SFRP1 in the modulation of TMPRSS2-ERG fusion gene in prostate cancer cell lines M. Rodriguez-Dorantes, C. D. Cruz-Hernandez, C. D. P. Garcia-Tobilla, S. Solorzano-Rosales P25 Targeted Methylation Sequencing of Prostate Cancer N. Jäger, J. Chen, R. Haile, M. Hitchins, J. D. Brooks, M. Snyder P26 Mutant TPMT alleles in children with acute lymphoblastic leukemia from México City and Yucatán, Mexico S. Jiménez-Morales, M. Ramírez, J. Nuñez, V. Bekker, Y. Leal, E. Jiménez, A. Medina, A. Hidalgo, J. Mejía P28 Genetic modifiers of Alström syndrome J. Naggert, G. B. Collin, K. DeMauro, R. 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Marqueurs chromosomiques: à propos d'un cas

Les marqueurs chromosomiques peuvent être définis comme des petits chromosomes de structure anormale présents en addition aux 46 chromosomes humains connus. C'est un groupe hétérogène d'anomalies de structure chromosomique pouvant être avec ou sans conséquence phénotypique. Plusieurs tentatives sont réalisées afin de retrouver une corrélation génotype-phénotype lors de la présence d'un marqueur chromosomique. L'identification du marqueur, son origine et sa structure suit une stratégie bien codifiée actuellement allant d'abord de l'orientation clinique suivie des techniques de cytogénétique conventionnelle (caryotype métaphasique standard, bandes C, NOR) et de cytogénétique moléculaire (M-FISH, CGH, CGH array) puis une détection par des techniques plus ciblées (painting, sondes locus spécifique). Cet ensemble permet une meilleure analyse et correspondance clinico-génétique. Nous rapportons le cas d'un nourrisson présentant une dysmorphie faciale avec un retard psychomoteur dont l'analyse cytogénétique a révélé la présence d'un marqueur chromosomique avec un caryotype métaphasique 47,XX,+mar. A travers cette observation, nous mettons en valeur le rôle de la cytogénétique conventionnelle et moléculaire dans le diagnostic des syndromes dysmorphiques permettant une meilleure prise en charge du patient et un conseil génétique adéquat pour sa famille

[The Cri du Chat syndrome: report of an observation]

Le syndrome du Cri du Chat (Cri du Chat syndrome, CdCS) est une anomalie chromosomique résultant d’une délétion de taille variable de l’extrémité du bras court du chromosome 5 (5p), incluant une région critique située en p15.2. Il représente une des délétions chromosomiques les plus fréquentes, son incidence dans la population générale est de 1/20 000 à 1/50 000. Les caractéristiques cliniques comprennent un cri monochromatique aigu, une microcéphalie, une dysmorphie cranio-faciale caractéristique évoluant avec l’âge et un retard mental et psychomoteur important. La taille de la délétion est variable, Le traitement est fonction des différents symptômes. Un remaniement chromosomique parental est retrouvé dans 12% des cas et la majorité des délétions responsables de la maladie du cri-du-chat surviennent de novo. Nous présentons une observation d’un syndrome du Cri du Chat, confirmé par caryotype métaphasique (46,XY,del(5)(p13) de novo). A travers cette observation nous mettrons à jour, les actualités scientifiques de ce rare syndrome, ainsi que la place des explorations cytogénétiques dans le diagnostic précis et le conseil génétique des syndromes dysmorphiques.

[Microdeletion syndromes (Williams syndrome and deletion syndrome 22q11) at CHU Hassan II of Fez: report of 3 observations]

Les syndromes microdélétionnels sont définis par la présence d’une anomalie chromosomique de taille mineure (inférieure à 5 mégabases) ou aneusomie segmentaire, décelable par cytogénétique moléculaire (FISH : Fluorescent in Situ Hybridization). Les syndromes microdélétionnels représentent des syndromes cliniques avec des phénotypes suffisamment caractéristiques pour être reconnus cliniquement. Actuellement la FISH est la technique de choix pour rechercher ces syndromes. Plusieurs syndromes microdélétionnels peuvent être confirmés aisément, les plus recherchés sont Le syndrome de Williams (microdélétion en 7q11.23) et le syndrome de la délétion 22q11 (microdélétion en 22q11.2). Le syndrome de Williams est caractérisé par une anomalie du développement qui associe un retard psycho-moteur, une dysmorphie du visage évocatrice et un profil cognitif et comportemental spécifique, une sténose aortique supravalvulaire -SASV- le plus souvent. Le Syndrome de la délétion 22q11 se caractérise par l’association de plusieurs malformations d’expression variable: une cardiopathie congénitale de type conotroncal, une dysmorphie faciale discrète mais caractéristique et une hypoplasie du thymus et des parathyroïdes. Nous rapportons nos premières observations au CHU Hassan II confirmées par FISH : Syndrome de la délétion 22q11 (n:2) et un syndrome de Williams. Le but de cet article est la mise à jour de nos connaissances sur ces deux syndromes et la mise en valeur du rôle de la cytogénétique moléculaire dans le diagnostic et le conseil génétique des syndromes microdélétionnels.