CAGI, the Critical Assessment of Genome Interpretation, establishes progress and prospects for computational genetic variant interpretation methods

BACKGROUND

The Critical Assessment of Genome Interpretation (CAGI) aims to advance the state-of-the-art for computational prediction of genetic variant impact, particularly where relevant to disease. The five complete editions of the CAGI community experiment comprised 50 challenges, in which participants made blind predictions of phenotypes from genetic data, and these were evaluated by independent assessors.

RESULTS

Performance was particularly strong for clinical pathogenic variants, including some difficult-to-diagnose cases, and extends to interpretation of cancer-related variants. Missense variant interpretation methods were able to estimate biochemical effects with increasing accuracy. Assessment of methods for regulatory variants and complex trait disease risk was less definitive and indicates performance potentially suitable for auxiliary use in the clinic.

CONCLUSIONS

Results show that while current methods are imperfect, they have major utility for research and clinical applications. Emerging methods and increasingly large, robust datasets for training and assessment promise further progress ahead.

Association between Pancreatoblastoma and Familial Adenomatous Polyposis: Review of the Literature with an Additional Case

BACKGROUND

Adult pancreatoblastoma (PBL) is a rare pancreatic malignancy, with recent evidence suggesting a possible link to familial adenomatous polyposis (FAP). This study aims to review the latest evidence and explore a possible association between adult PBL and FAP.

METHODS

Two independent literature reviews were conducted: (1) on PBL and FAP, and (2) on PBL in the adult population not diagnosed with FAP.

RESULTS

Out of 26 articles on PBL and FAP screened, 5 were selected for systematic review, including 1 additional case. We identified eight FAP-related PBL cases, with a median age of 40 (IQR: 34-50). Of these, seven (87%) occurred in adults. We found 65 cases of adult PBL not FAP-related; thus, 7 out of 65 cases (10.7%) of adult PBL reported in the literature are associated with a clinical diagnosis of FAP or were carriers of APC germline pathogenic variants (GPVs).

CONCLUSION

Data suggest a non-random association between adult PBL and FAP. Further research is essential to optimise surveillance protocols and develop more effective treatment strategies.

A Novel FLCN Variant in a Suspected Birt-Hogg-Dubè Syndrome Patient

Subjects with pathogenic (PV) and likely pathogenic (LPV) FLCN variants have an increased risk of manifesting benign and malignant disorders that are related to Birt-Hogg-Dubé syndrome (BHDS): an autosomal dominantly inherited disorder whose severity can vary significantly. Renal cell carcinoma (RCC) development in BHD (Birt-Hogg-Dubé) patients has a very high incidence; thus, identifying this rare syndrome at early stages and preventing metastatic spread is crucial. Over the last decade, the advancement of Next Generation Sequencing (NGS) and the implementation of multigene panels for hereditary cancer syndromes (HCS) have led to a subsequent focus on additional genes and variants, including those of uncertain significance (VUS). Here, we describe a novel FLCN variant observed in a subject manifesting disorders that were suspected to be related to BHDS and with a family history of multiple cancers.

Filling the gap: A thorough investigation for the genetic diagnosis of unsolved polyposis patients with monoallelic MUTYH pathogenic variants

Backgrounds

MUTYH‐associated polyposis (MAP) is an autosomal recessive disease caused by biallelic pathogenic variants (PV) of the MUTYH gene. The aim of this study was to investigate the genetic causes of unexplained polyposis patients with monoallelic MUTYH PV. The analysis focused on 26 patients with suspected MAP, belonging to 23 families. Ten probands carried also one or more additional MUTYH variants of unknown significance.

Methods

Based on variant type and on the collected clinical and molecular data, these variants were reinterpreted by applying the ACMG/AMP rules. Moreover, supplementary analyses were carried out to investigate the presence of other variants and copy number variations in the coding and promoter regions of MUTYH, as well as other polyposis genes (APC, NTHL1, POLE, POLD1, MSH3, RNF43, and MCM9).

Results

We reclassified 4 out of 10 MUTYH variants as pathogenic or likely pathogenic, thus supporting the diagnosis of MAP in only four cases. Two other patients belonging to the same family showed a previously undetected deletion of the APC gene promoter. No PVs were found in the other investigated genes. However, 6 out of the 18 remaining families are still interesting MAP candidates, due to the co‐presence of a class 3 MUTYH variant that could be reinterpreted in the next future.

Conclusion

Several efforts are necessary to fully elucidate the genetic etiology of suspected MAP patients, especially those with the most severe polyposis/tumor phenotype. Clinical data, tumor molecular profile, family history, and polyposis inheritance mode may guide variant interpretation and address supplementary studies.

Further delineation and long-term evolution of electroclinical phenotype in Mowat Wilson Syndrome. A longitudinal study in 40 individuals

BACKGROUND

Epilepsy is a main feature of Mowat Wilson Syndrome (MWS), a congenital malformation syndrome caused by ZEB2 variants. The aim of this study was to investigate the long-term evolution of the electroclinical phenotype of MWS in a large population.

METHODS

Forty-individuals with a genetically confirmed diagnosis were enrolled. Three age groups were identified (t1 = 0-4; t2 = 5-12; t3 = >13 years); clinical data and EEG records were collected, analyzed, and compared for age group. Video-EEG recorded seizures were reviewed.

RESULTS

Thirty-six of 40 individuals had epilepsy, of whom 35/35 aged >5 years. Almost all (35/36) presented focal seizures at onset (mean age at onset 3.4 ± 2.3 SD) that persisted, reduced in frequency, in 7/22 individuals after the age of 13. Absences occurred in 22/36 (mean age at onset 7.2 ± 0.9 SD); no one had absences before 6 and over 16 years old. Paroxysmal interictal abnormalities in sleep also followed an age-dependent evolution with a significant increase in frequency at school age (p = 0.002) and a reduction during adolescence (p = 0.008). Electrical Status Epilepticus during Sleep occurred in 14/36 (13/14 aged 5-13 years old at onset). Seven focal seizure ictal video-EEGs were collected: all were long-lasting and more visible clinical signs were often preceded by prolonged electrical and/or subtle (erratic head and eye orientation) seizures. Valproic acid was confirmed as the most widely used and effective drug, followed by levetiracetam.

CONCLUSIONS

Epilepsy is a major sign of MWS with a characteristic, age-dependent, electroclinical pattern. Improvement with adolescence/adulthood is usually observed. Our data strengthen the hypothesis of a GABAergic transmission imbalance underlying ZEB2-related epilepsy.

Refinement of the clinical and mutational spectrum of UBE2A deficiency syndrome

UBE2A deficiency, that is, intellectual disability (ID) Nascimento type (MIM 300860), is an X-linked syndrome characterized by developmental delay, moderate to severe ID, seizures, dysmorphisms, skin anomalies, and urogenital malformations. Forty affected subjects have been reported thus far, with 31 cases having intragenic UBE2A variants. Here, we report on additional eight affected subjects from seven unrelated families who were found to be hemizygous for previously unreported UBE2A missense variants (p.Glu62Lys, p.Arg95Cys, p.Thr99Ala, and p.Arg135Trp) or small in-frame deletions (p.Val81_Ala83del, and p.Asp101del). A wide phenotypic spectrum was documented in these subjects, ranging from moderate ID associated with mild dysmorphisms to severe features including congenital heart defects (CHD), severe cognitive impairment, and pineal gland tumors. Four variants affected residues (Glu62, Arg95, Thr99 and Asp101) that contribute to stabilizing the structure of the E3 binding domain. The three-residue in-frame deletion, p.Val81_Ala83del, resulted from aberrant processing of the transcript. This variant and p.Arg135Trp mapped to regions of the protein located far from the E3 binding region, and caused variably accelerated protein degradation. By reviewing available clinical information, we revise the clinical and molecular profile of the disorder and document genotype-phenotype correlations. Pineal gland cysts/tumors, CHD and hypogammaglobulinemia emerge as recurrent features.

Characterization of intellectual disability and autism comorbidity through gene panel sequencing

Intellectual disability (ID) and autism spectrum disorder (ASD) are clinically and genetically heterogeneous diseases. Recent whole exome sequencing studies indicated that genes associated with different neurological diseases are shared across disorders and converge on common functional pathways. Using the Ion Torrent platform, we developed a low-cost next-generation sequencing gene panel that has been transferred into clinical practice, replacing single disease-gene analyses for the early diagnosis of individuals with ID/ASD. The gene panel was designed using an innovative in silico approach based on disease networks and mining data from public resources to score disease-gene associations. We analyzed 150 unrelated individuals with ID and/or ASD and a confident diagnosis has been reached in 26 cases (17%). Likely pathogenic mutations have been identified in another 15 patients, reaching a total diagnostic yield of 27%. Our data also support the pathogenic role of genes recently proposed to be involved in ASD. Although many of the identified variants need further investigation to be considered disease-causing, our results indicate the efficiency of the targeted gene panel on the identification of novel and rare variants in patients with ID and ASD.

Toward a better definition of EPCAM deletions in Lynch Syndrome: Report of new variants in Italy and the associated molecular phenotype

Background

Inherited epimutations of Mismatch Repair (MMR) genes are responsible for Lynch Syndrome (LS) in a small, but well defined, subset of patients. Methylation of the MSH2 promoter consequent to the deletion of the upstream EPCAM gene is found in about 1%–3% of the LS patients and represents a classical secondary, constitutional and tissue‐specific epimutation. Several different EPCAM deletions have been reported worldwide, for the most part representing private variants caused by an Alu‐mediated recombination.

Methods

712 patients with suspected LS were tested for MMR mutation in our Institute. EPCAM deletions were detected by multiplex ligation‐dependent probe amplification (MLPA) and then defined by Long‐Range polymerase chain reaction (PCR)/Sanger sequencing. A comprehensive molecular characterization of colorectal cancer (CRC) tissues was carried out by immunohistochemistry of MMR proteins, Microsatellite Instability (MSI) assay, methylation specific MLPA and transcript analyses. In addition, somatic deletions and/or variants were investigated by MLPA and next generation sequencing (NGS).

Results

An EPCAM deletion was found in five unrelated probands in Italy: variants c.556‐490_*8438del and c.858+1193_*5826del are novel; c.859‐1430_*2033del and c.859‐670_*530del were previously reported. All probands were affected by CRC at young age; tumors showed MSI and abnormal MSH2/MSH6 proteins expression. MSH2 promoter methylation, as well as aberrant in‐frame or out‐of‐frame EPCAM/MSH2 fusion transcripts, were detected in CRCs and normal mucosae.

Conclusion

An EPCAM deletion was the causative variant in about 2% of our institutional series of 224 LS patients, consistent with previously estimated frequencies. Early age and multiple CRCs was the main clinical feature of this subset of patients.

Molecular cytogenetics characterization of seven small supernumerary marker chromosomes derived from chromosome 19: Genotype-phenotype correlation and review of the literature

Only a few subjects carrying supernumerary marker chromosomes derived from 19 chromosome (sSMC(19)) have been described to date and for a small portion of them the genic content has been defined at the molecular level. We present seven new different sSMCs(19) identified in eight individuals, seven of whom unrelated. The presence of the sSMC is associated with a clinical phenotype in five subjects, while the other three carriers, two of whom related, are normal. All sSMCs(19) have been characterized by means of conventional and molecular cytogenetics. We compare the sSMCs(19) carriers with a clinical phenotype to already described patients with gains (sSMCs or microduplications) of overlapping genomic regions with the aim to deepen the pathogenicity of the encountered imbalances and to assess the role of the involved genes on the phenotype. The present work supports the correlation between the gain of some chromosome 19 critical regions and specific phenotypes.

In utero ultrasound diagnosis of corpus callosum agenesis leading to the identification of orofaciodigital type 1 syndrome in female fetuses

BACKGROUND

OFD1 syndrome is a rare ciliopathy inherited on a dominant X-linked mode, typically lethal in males in the first or second trimester of pregnancy. It is characterized by oral cavity and digital anomalies possibly associated with cerebral and renal signs. Its prevalence is between 1/250,000 and 1/50,000 births. It is due to heterozygous mutations of OFD1 and mutations are often de novo (75%). Familial forms show highly variable phenotypic expression. OFD1 encodes a protein involved in centriole growth, distal appendix formation, and ciliogenesis.

CASES

We report the investigation of three female fetuses in which corpus callosum agenesis was detected by ultrasound during the second trimester of pregnancy. In all three fetuses, fetopathological examination allowed the diagnosis of OFD1 syndrome, which was confirmed by molecular analysis.

CONCLUSIONS

To our knowledge, these are the first case reports of antenatal diagnosis of OFD1 syndrome in the absence of familial history, revealed following detection of agenesis of the corpus callosum. They highlight the impact of fetal examination following termination of pregnancy for brain malformations. They also highlight the contribution of ciliary genes to corpus callosum development.

Neuroimaging findings in Mowat-Wilson syndrome: a study of 54 patients

PURPOSE

Mowat-Wilson syndrome (MWS) is a genetic disease characterized by distinctive facial features, moderate to severe intellectual disability, and congenital malformations, including Hirschsprung disease, genital and eye anomalies, and congenital heart defects, caused by haploinsufficiency of the ZEB2 gene. To date, no characteristic pattern of brain dysmorphology in MWS has been defined.

METHODS

Through brain magnetic resonance imaging (MRI) analysis, we delineated a neuroimaging phenotype in 54 MWS patients with a proven ZEB2 defect, compared it with the features identified in a thorough review of published cases, and evaluated genotype-phenotype correlations.

RESULTS

Ninety-six percent of patients had abnormal MRI results. The most common features were anomalies of corpus callosum (79.6% of cases), hippocampal abnormalities (77.8%), enlargement of cerebral ventricles (68.5%), and white matter abnormalities (reduction of thickness 40.7%, localized signal alterations 22.2%). Other consistent findings were large basal ganglia, cortical, and cerebellar malformations. Most features were underrepresented in the literature. We also found ZEB2 variations leading to synthesis of a defective protein to be favorable for psychomotor development and some epilepsy features but also associated with corpus callosum agenesis.

CONCLUSION

This study delineated the spectrum of brain anomalies in MWS and provided new insights into the role of ZEB2 in neurodevelopment.Genet Med advance online publication 10 November 2016.

Angiomi cavernosi multipli cerebrali ed epatici

Gli angiomi cavernosi cerebrali (ACC) sono una delle malformazioni vascolari del SNC meno frequenti. É nota peraltro la possibilità di ricorrenza familiare con modalità di trasmissione autosomica dominante. Presentiamo una famiglia italiana, seguita lungamente nel tempo, in cui 10 soggetti in 4 generazioni presentano ACC.

Il reperto cerebrale era associato ad angioma cavernoso epatico (ACE) in 2 soggetti e ad angioma cavernoso retinico (ACR) in uno.

La TC, eseguita in 9 soggetti, ha dimostrato una maggior capacità rispetto alla RM di rilevare le calcificazioni spesso presenti in queste malformazioni; la RM ha evidenziato d'altra parte un numero maggiore di cavernomi, soprattutto in sede sottotentoriale. 7 pazienti sono stati sottoposti ad esame angiografico con tecnica digitale sottrattiva. In nessun caso è stata dimostrata malformazione angiomatosa di tipo artero-venoso ed in 1 solo caso è stata rilevata una lieve persistenza di contrasto nelle fasi capillare-venose.

Riteniamo meritevole di segnalazione questa famiglia per:

l'associazione di ACC con ACE segnalata in 1 solo caso in letteratura (Filling - Katz) e la contemporanea associazione, pur in un solo paziente, di ACR; la costante molteplicità delle lesioni cerebrali, quasi sempre presenti sia in sede sopra che sottotentoriale; il contrasto tra la povertà dei sintomi e l'imponenza del quadro radiologico e la sua variabilità espressiva nelle diverse generazioni; l'elevato numero di soggetti affetti rispetto ad altre famiglie riportate in letteratura.

I rilievi clinico-radiologici nella presente casistica ed i dati riportati dalla letteratura suggeriscono la necessità di uno studio neuroradiologico complementare TC ed RM nei soggetti affetti da ACC e nei familiari.

Va peraltro tenuta presente la possibilità attuale di selezionare i pazienti da sottoporre ad angiografia tradizionale sulla base dei reperti ottenibili con angio-RM. Va sottolineata infine l'opportunità di una attenta e ponderata valutazione della terapia chirurgica proposta da molti autori, data la relativa benignità del decorso clinico riscontrata nei soggetti della nostra serie casistica.

Epilepsy in Mowat-Wilson syndrome: delineation of the electroclinical phenotype

Mowat-Wilson syndrome (MWS) is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene and is characterized by distinctive facial features, epilepsy, moderate to severe intellectual disability, corpus callosum abnormalities and other congenital malformations. Epilepsy is considered a main manifestation of the syndrome, with a prevalence of about 70-75%. In order to delineate the electroclinical phenotype of epilepsy in MWS, we investigated epilepsy onset and evolution, including seizure types, EEG features, and response to anti-epileptic therapies in 22 patients with genetically confirmed MWS. Onset of seizures occurred at a median age of 14.5 months (range: 1-108 months). The main seizure types were focal and atypical absence seizures. In all patients the first seizure was a focal seizure, often precipitated by fever. The semiology was variable, including hypomotor, versive, or focal clonic manifestations; frequency ranged from daily to sporadic. Focal seizures were more frequent during drowsiness and sleep. In 13 patients, atypical absence seizures appeared later in the course of the disease, usually after the age of 4 years. Epilepsy was usually quite difficult to treat: seizure freedom was achieved in nine out of the 20 treated patients. At epilepsy onset, the EEGs were normal or showed only mild slowing of background activity. During follow-up, irregular, diffuse frontally dominant and occasionally asymmetric spike and waves discharges were seen in most patients. Sleep markedly activated these abnormalities, resulting in continuous or near-to-continuous spike and wave activity during slow wave sleep. Slowing of background activity and poverty of physiological sleep features were seen in most patients. Our data suggest that a distinct electroclinical phenotype, characterized by focal and atypical absence seizures, often preceded by febrile seizures, and age-dependent EEG changes, can be recognized in most patients with MWS.

Factors affecting the treatment of multiple colorectal adenomas

BACKGROUND

Currently, no guidelines exist for the treatment of patients with multiple colorectal adenomas (MCRAs) (>10 but <100 synchronous nondiminutive polyps of the large bowel). This retrospective study aimed to investigate the clinical and molecular factors related to different treatments for MCRAs.

METHODS

Patients with MCRAs were consecutively enrolled from January 2003 to June 2011. Sequencing of their APC and MutYH genes was performed. The clinical, molecular, and family histories of the patients were collected using the Progeny database. The patient treatments were divided into three groups of increasing clinical weight: endoscopic polypectomy, segmental resection, and total colectomy. A logistic regression analysis of clinicomolecular factors related to different treatment options was performed.

RESULTS

The study comprised 80 patients (32 women, 40%) with a median age of 53 years (range 13-74 years). The median number of polyps was 33 (range 10-90).The cases included 62 diffuse polyposis, 18 segmental polyposis coli and synchronous colorectal carcinomas (CRC; 34 cases, 43%). The pathogenetic mutations were biallelic MutYH (n = 19, 24%) and APC (n = 4, 5%). The mean follow-up period was 74 months (median 43 months, range 1-468 months). Endoscopic polypectomy was performed in 25 cases (31%), segmental resection in 16 cases (20%), and total colectomy in 39 cases (49%). The logistics regression analysis, considering all the patients, showed that the number of polyps, the presence of CRC, and mutation were correlated with more intensive treatment. For the patients without CRC, only the number of polyps was correlated with the severity of the treatment (p > 0.0166). "On the ROC (receiver operating characteristic) curve, 25 was the number of polyps that best discriminated between surgical and endoscopic therapy.

CONCLUSIONS

The majority of patients with MCRAs undergo surgery. For patients without CRC, only the number of polyps, and not the presence of a disease-causing mutation, is correlated with increased heaviness of treatment. Patients with more than 25 polyps are more likely to undergo a surgical resection.

Familial subtelomeric rearrangement of chromosomes 19 and 20: a new contribution to partial distal 19q trisomy

The role of cryptic translocations in human syndromes is a matter of fact, though this phenomenon is apparently rare. Apart from episodic case reports due to the increasing application of new molecular cytogenetic techniques, no data on its frequency in the general population are currently available. Rearrangements due to the unbalanced segregation of cryptic translocations are found in many anomalies responsible for different clinical pictures. In nearly 50% of cases, subtelomeric abnormalities are inherited from a parent carrying a balanced cryptic chromosome rearrangement. To date, very few cases of partial trisomies of 19q have been reported, with different breakpoints. Involvement of the distal region 19q is even more rare, and the delineation of its main clinical characteristics is still vague and awaiting better definition. We report two new cases of partial 19q13.42-qter trisomy associated with a partial 20p13-pter monosomy in a family found to have the cryptic translocation t(19;20)(q13.42;p13). We investigated a 5-year-old boy and his 49-year-old paternal uncle, and both had a similar, previously unrecognized mental retardation pattern, associated with the same subtelomeric rearrangement.

Vertebral and spinal cavernous angiomas associated with familial cerebral cavernous malformation

BACKGROUND

Cerebral cavernous malformations are vascular malformations that affect the CNS and have been associated with cutaneous, retinal, and hepatic lesions. Until now, vertebral hemangiomas associated with CCM have been described only in one case. The coexistence of intracranial and spinal cavernous angiomas in familial CCM is extremely rare. In addition to previous studies, the occurrence of spinal, vertebral, and cutaneous cavernous angiomas is now described in different members of a large family with CCM.

CASE DESCRIPTION

Our study reports a previously described family (IFCAS-07) with 12 members affected by autosomal dominant cavernous angiomas: 11 had CCM either alone or associated with hepatic or retinal angiomas, and one had only hepatic angioma. In all 11 members affected by CCM, the mutation of CCM1 gene was detected. During the follow-up, 8 subjects underwent a spinal MRI: 2 because they were symptomatic (thoracic paresthesias, enuresis, back pain) and 6 as a screening examination. Spinal MRI showed in 5 subjects spinal cavernous angiomas either alone or associated with vertebral hemangiomas.

CONCLUSIONS

To our knowledge, this is the largest family reported with different subjects affected by CCM associated with multiple cavernous angiomas throughout (brain and spinal cord) and besides (retina, skin, liver, and vertebral column) the CNS. Comprehensive care of patients with familial CCM includes screening of all the tissues that can be affected and appropriate management by specialists. We emphasize the importance of spinal MRI in the diagnosis of spinal and vertebral cavernous angiomas in all patients affected by familial CCM.

Utilization of genetic counseling by parents of a child or fetus with congenital malformation in North-East Italy

Congenital malformations (CM) affect 2-3% of all births, the cause of which, when known, is genetic in 80-90% of cases. A genetic consultation (GC) is indicated for the parents of a child affected by a CM. This study analyzes the parental utilization of genetic counseling (GCU) and its possible influencing factors after termination of pregnancy (TOP) because of fetal anomalies or after the birth of a child affected by a major malformation. The study concerns cases in North-East Italy where there is a CM registry and a center-satellite system for genetic counseling. The results of this analysis are also compared to other similar studies, which address the same topic. Between 1981 and 2000, 1,235 out of 14,888 GC were performed because of the presence of a CM in a child/fetus. In the same period, 4,933 births and 1,112 TOPs were registered. The overall GCU was 19%, with significant differences according to malformative phenotype, severity of the malformative condition, type of birth, and viability. Genetic counseling was performed significantly sooner following TOP than after the birth of a malformed child. GCU showed an unequal distribution according to the parents' place of residence, suggesting that easy and equal access to the genetic service was probably not well provided for. Our results suggest that genetic services should be integrated with related services, and that the public and physicians need a greater awareness of these services.

CCM1 gene mutations in families segregating cerebral cavernous malformations

Cerebral cavernous malformations (CCM) are vascular anomalies, sometimes inherited as an autosomal dominant trait, which can cause strokes and seizures. Recently, mutations of the CCM1 gene (chromosome 7q) have been found in a subset of families. The authors found 10 new mutations by screening 29 families and five seemingly sporadic cases of CCM. The mutations predicted truncation of the Krit1 mRNA encoded by CCM1, supporting the contention that CCM result from loss of Krit1 protein function and the possibility that this protein acts as a tumor suppressor.

Neurofibromatosis type 1 growth charts

Growth abnormalities such as macrocephaly and short stature have been described and are considered a consistent finding in neurofibromatosis type 1 (NF1), one of the most common autosomal dominant disorders in man. We present here a clinical study on the growth profile of a sample of NF1 patients collected through a population-based registry that covers three contiguous regions of North-East Italy (NEI-NF Registry). Auxometric traits of 528 NF1 patients have been measured with the aim of drawing growth charts for height, weight, and head circumference (OFC). Height velocity charts were based on a subset of 143 children who underwent multiple measurements. No differences in height were apparent between NF1 and normal subjects up to age 7 (girls) and 12 (boys) years; subsequently, the 50th centile of NF1 subjects tends to overlap with the 25th centile of normal subjects, and the 3rd centile is much lower in NF1 subjects than in normal subjects, mainly during adolescence. The negatively skewed distribution of height seems to indicate that height growth impairment affects only a proportion of NF1 subjects; height growth impairment does not seem related to disease severity. As for weight, our data suggest that slight overweight is a characteristic of adult NF1 subjects (mainly among males), independent of disease severity. Height growth velocity is normal during childhood for both sexes, whereas the pubertal spurt is slightly anticipated and reduced in NF1 boys but not in girls. Our data confirm previous observations that macrocrania affects most NF1 subjects; the shape of the head growth curve is similar in NF1 and normal girls, whereas NF1 boys present an OFC pubertal growth spurt much more pronounced and delayed than normal boys. The disproportion between OFC and height seems to be related to disease severity in boys but not in girls. Growth charts presented here can be useful in neurofibromatosis clinics for the identification of the effects of secondary growth disorders, for growth prognosis, and for the evaluation of the effects of a therapy such as GH therapy after radiotherapy for optic glioma.

Rhabdomyosarcoma in a patient with cardio-facio-cutaneous syndrome

A boy with characteristic facial features, pulmonary valvular stenosis, ectodermal abnormalities, growth failure, and mental retardation was admitted for intestinal occlusion at 20 months of age. Clinical findings were consistent with a diagnosis of cardio-facio-cutaneous syndrome (CFC-s), and a huge abdominal mass was evident on computed tomography scan. A biopsy was performed, and embryonal rhabdomyosarcoma was diagnosed. Molecular analysis was performed by reverse transcription (RT) polymerase chain reaction (PCR) on tumor RNA to seek the chimerical transcript of the most common soft tissue sarcoma translocations and analyze neurofibromatosis 1 (NF1) gene expression. Translocations involving 1;13, 2;13, and 11;22 were not found, and the specific transcripts of the NF1 gene were present. Chemotherapy was implemented, but the child died 7 months later of tumor progression. Few patients with CFC-s have been described, and their follow-up is not well known. The association of CFC-s with rhabdomyosarcoma has not been reported previously, but other neoplasms have been reported in patients with Noonan syndrome, a condition similar to CFC-s. More observations are needed, but this and other reports suggest there could be a higher risk of malignancy in patients with syndromes in the Noonan phenotype category.

Methimazole embryopathy: delineation of the phenotype

We report on a further case of congenital anomalies in a child exposed to methimazole during the first trimester of pregnancy (from first to seventh gestational week), and define a specific malformation pattern related to prenatal methimazole exposure and consisting of choanal and esophageal atresia, scalp defects, minor facial anomalies and psychomotor delay.

Cardiovascular anomaly in Rieger Syndrome: heterogeneity or contiguity?

PURPOSE

Rieger Syndrome (RS) is an autosomal dominant disease, in which Axenfeld's and Rieger's anomalies are associated with typical facial dysmorphism and other extra-ocular findings. Cardiovascular defects are considered an occasional finding in this syndrome.

METHODS

We describe a RS case in which the typical ocular and dysmorphic features were associated with bicuspid aortic valve. A review of the literature is provided.

RESULTS

A total of 15 other cases of Axenfeld's or Rieger's anomaly associated with cardiovascular defects have been reported. In the cases in which the diagnosis of RS could be clinically performed, the cardiac defect mostly involved the outflow tract structures.

CONCLUSION

The hypothesis that this association could be non-coincidental is discussed. The proved genetic heterogeneity of RS, based on clinical and molecular evidence, may suggest that RS is a contiguous gene syndrome or RS with cardiac defect is a separate entity. Finally we suggest a careful cardiological evaluation in RS patients, to assess the real frequency of cardiac defects in this syndrome.

Mutation producing alternative splicing of exon 26 in the COL1A2 gene causes type IV osteogenesis imperfecta with intrafamilial clinical variability

We have characterized a familial form of osteogenesis imperfecta (OI). Following the identification by ultrasound of short limbs and multiple fractures in a fetus at 25 weeks of gestation, the family was referred with a provisional diagnosis of severe OI. We detected subtle clinical and radiological signs of OI in the father and in the paternal grandmother of the proposita, who had never received a diagnosis of OI. Linkage analysis indicated COL1A2 as the disease locus. Heteroduplex analysis of reverse transcription-polymerase chain reaction (RT-PCR) amplification products of pro alpha2(I) mRNA from an affected member and subsequent sequencing of the candidate region demonstrated the presence of normal transcripts and a minority of transcripts lacking exon 26 (54 bp) of COL1A2. Sequencing of PCR-amplified genomic DNA identified an A --> G transition in the moderately conserved +3 position of the IVS 26 donor splice site. The mutant pre-mRNA molecules were alternatively spliced, yielding both full-length and deleted transcripts that represented less than 30% of the total pro alpha2(I) mRNA. The biochemical data on type I collagen synthesized by dermal fibroblasts showed intracellular retention of the mutant protein; failure to detect the shortened alpha2(I) chains either in the medium or in the cell layer may be the consequence of their instability at physiological temperature. These observations justified the mild resulting phenotype.

Family with branchial arch anomalies, hearing loss, ear and commissural lip pits, and rib anomalies. A new autosomal recessive condition: branchio-oto-costal syndrome?

We report on a family in which 3 sibs were affected with conductive deafness, bilateral preauricular and commissural lip pits, monolateral branchial fistula, and rib anomalies. On the basis of parental consanguinity, lack of clinical variability and affected subjects of both sexes, this condition seems to be inherited as an autosomal recessive trait. We suggest that these findings comprise a new autosomal recessive entity of branchial, auricular and costal anomalies, for which we suggest the acronym BOC (branchio-oto-costal) syndrome.

Anesthesiologic problems in Williams syndrome: the CACNL2A locus is not involved

We present the case of a patient affected with Williams syndrome (WS), who developed a suspected malignant hyperthermia (MH) reaction to general anesthesia. The proximity to the WS region of the gene encoding the L-type voltage-gated calcium channel alpha 2/delta-subunit (CACNL2A) on 7q11.23-q21.1, previously shown to be closely linked to some forms of MH susceptibility, prompted us to investigate whether this gene is deleted in WS. Linkage studies and fluorescence in situ hybridization analysis demonstrated that the CACNL2A locus is localized outside the WS deleted region.

Familial cerebral, hepatic, and retinal cavernous angiomas: a new syndrome

New, non-invasive neuroradiological techniques [computed tomography (CT) and magnetic resonance (MR)] have led to reassessment of the incidence of cavernous angioma of the brain (CCA), which is sometimes multiple and associated with cavernomas in other organs. CCA is known to be familial, with dominant autosomal transmission. This paper concerns a family with multiple CCA, sometimes in association with liver angiomas, in ten members belonging to four different generations. These malformations can vary in clinical expression: no neurological symptoms have been detected in subjects from the first or second generations, but they were found in adult age in subjects from the third generation; two fourth-generation patients came under our observation at 2.5 years of age. Symptoms include partial epileptic fits, which sometimes become generalized later and which are generally controlled adequately by therapy. Patients also present paresthesia and occasional motor deficiencies corresponding to CCA bleeding episodes; these symptoms have always abated with medical treatment alone. None of the patients are mentally retarded or restricted in their daily lives. Neuroradiological investigations (CT, MR, angiography) reveal typical multiple brain lesions in all patients. Given the first-generation patient's clinical history of symptomatic hepatomegaly and the postmortem finding of multiple liver and brain cavernomas, liver ultrasonography was performed on all members of the family. Liver angioma was detected in two subjects from the second and third generations. Retinal angioma was detected in one patient with quadrantanopsia.(ABSTRACT TRUNCATED AT 250 WORDS)

Is visual field reduction a component manifestation of osteopathia striata with cranial sclerosis?

A girl with fully expressed osteopathia striata with cranial sclerosis (OS) was also found to have a contraction of the two visual fields, a sign never previously described in OS syndrome. We suggest that the visual field defect is a component manifestation of OS syndrome, whose pathogenesis is represented by distortion of the optic canal and narrowing of the optic foramina.

Clinical anophthalmia: an epidemiological study in northeast Italy based on 368,256 consecutive births

We describe an epidemiological and clinical study of Clinical Anophthalmia in a population of consecutive live and stillborns enrolled in a hospital based registry of congenital malformations in Northeast Italy during the period from 1981 to 1989; 22 cases were detected among 368,256 births yielding a birth prevalence of 0.60 per 10,000 (95% CI 0.34-0.84); 20 cases were associated with at least one other major malformation. Malformation syndrome, association, or sequence was diagnosed in 13, while a non-recognizable multiple defect pattern was observed in 7/20 (35%). A chromosomal anomaly was present in eight syndromic cases. No significant trend over time, nor space or time clusters, were detected. As most CAn cases are associated with other anomalies recognizable by ultrasound, a decreasing trend in its prevalence at birth is expected in the future.