Townes-Brocks syndrome with adult renal impairment in a Chinese family: A case report

BACKGROUND

Townes-Brocks syndrome (TBS) is a rare autosomal dominant syndrome that is characterized by a triad of imperforate anus, dysplastic ears, and thumb malformations. Heterozygous variants of SALL1 are responsible for this syndrome. Renal structural abnormalities and functional impairments are often reported in TBS patients.

CASE SUMMARY

We report a case of TBS in a Chinese family. The index patients showed obvious renal atrophy and renal failure. TBS was suggested after a physical examination and pedigree analysis. Whole exome sequencing revealed a heterozygous variant of SALL1. The variant (NM_001127892 c.1289_c.1290 insC) led to a read-frame shift of the encoded protein, which was confirmed by Sanger sequencing. The variant cosegregated with the phenotype among affected members.

CONCLUSION

A novel variant in SALL1 gene may be the molecular pathogenic basis of this disorder.

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

BACKGROUND

Infertility is a common and rapidly growing health issue around the world. The genetic analysis based on the infertile population is crucial for intervention and treatment.

OBJECTIVE

To find candidate gene locus led to azoospermia in Chinese multi-ethnic groups and provide theoretical guidance for the diagnosis of genetic diseases to progressively aggravated infertility patients and sterile offspring with ART.

METHODS

The study based on whole-exome sequencing (WES) was presented for genetic characteristic analysis of multi-ethnics and identification of variants related to infertility in Xinjiang area of China.

RESULTS

The frequency of pathogenic variants showed significant ethnic differences among four main ethnics in Xinjiang. The population structure analysis confirmed that the Hui was close to the Han population, the Kazak was close to the Uygur population, and there are three ancestry components in the four ethnics. In addition, ten candidate variants potentially regulated azoospermia were detected, and KNTC1 (rs7968222: G > T) was chosen to validate the association. Through the analysis in the valid group, the frequency of rs7968222 (G > T) has a significant difference in the azoospermia population (11.76%, 8/68) and normospermia population (4.63%, 35/756) (P < 0.001). Interestingly, the proportion of people with abnormal follicle-stimulating hormone (FSH) level in the group carrying rs7968222 (G > T) was significantly higher than non-carriers (P < 0.05). Therefore, rs7968222 may regulate spermatogenesis through affecting hormone level.

CONCLUSION

Our study establishes the genetics analysis of Northwest China and finds a candidate gene locus KNTC1 (rs7968222: G > T), which is one of the genetic susceptibility factors for male azoospermia.

Identification of 1q21.1 microduplication in a family: A case report

BACKGROUND

Copy number variation (CNV) has become widely recognized in recent years due to the extensive use of gene screening in developmental disorders and epilepsy research. 1q21.1 microduplication syndrome is a rare CNV disease that can manifest as multiple congenital developmental disorders, autism spectrum disorders, congenital malformations, and congenital heart defects with genetic heterogeneity.

CASE SUMMARY

We reported a pediatric patient with 1q21.1 microduplication syndrome, and carried out a literature review to determine the correlation between 1q21.1 microduplication and its phenotypes. We summarized the patient’s medical history and clinical symptoms, and extracted genomic DNA from the patient, her parents, elder brother, and sister. The patient was an 8-mo-old girl who was hospitalized for recurrent convulsions over a 2-mo period. Whole exon sequencing and whole genome low-depth sequencing (CNV-seq) were then performed. Whole exon sequencing detected a 1.58-Mb duplication in the CHR1:145883867-147465312 region, which was located in the 1q21.1 region. Family analysis showed that the pathogenetic duplication fragment, which was also detected in her elder brother’s DNA originated from the mother.

CONCLUSION

Whole exon sequencing combined with quantitative polymerase chain reaction can provide an accurate molecular diagnosis in children with 1q21.1 microduplication syndrome, which is of great significance for genetic counseling and early intervention.

Treatments and whole exon sequencing of a case with multiple primary lung cancer

INTRODUCTION

The number of patients with synchronous multiple primary lung cancer (sMPLC) has increased recently. However, diagnosing and selecting the appropriate therapeutic strategy for this type of disease is not simple.

CASE PRESENTATION

This report presented a case of sMPLC with lymph node metastasis. With no smoking and cancer history, this patient had seven nodules in the right lung and underwent single-portal video-assisted thoracoscopic surgery (VATS). In addition, she received four cycles of chemotherapy after the operation. Whole exon sequencing (WES) was performed in five resected tissue samples (four tumors and one lymph node). We conducted genomic profiling and clone evolution analysis of the five samples. Gene detection helped to confirm that the metastasis lymph node was transferred from one nodule. There was apparent heterogeneity of gene mutations among the five samples of the patient, with only one shared "neurofilament heavy polypeptide" (NEFH) mutation. A dominant substitution of C > T/G > A was found in all the samples. Pyclone model was used to calculate all tissues' cellular prevalence (CP) values, and NEFH mutations were thought to be the ancestral clones. During the follow-up period, residual lesions showed no apparent changes and limited response to chemotherapy.

CONCLUSIONS

This report showed an essential role in genomic detection and selecting the appropriate treatment of sMPLC. Surgery remains the primary treatment strategy for this type of disease, and the occurrence and development of sMPLC need more in-depth research.

Papillary renal neoplasm with reverse polarity-a comparative study with CCPRCC, OPRCC, and PRCC1

Papillary renal neoplasm with reverse polarity (PRNRP) is a newly defined entity with distinct histomorphology and recurrent KRAS mutation. In this study, we aimed to identify and analyze the clinicopathological, immunohistochemical (IHC), and molecular features of PRNRP in our center and to evaluate its differential diagnosis with other tumors with which it is easily confused: clear cell papillary renal cell carcinoma (CCPRCC), oncocytic papillary renal cell carcinoma (OPRCC), and papillary renal cell carcinoma type 1 (PRCC1). Nephrectomy specimens of PRNRP (n = 15), CCPRCC (n = 11), and OPRCC (n = 12) were retrieved from our pathology archives. We also selected typical cases of PRCC1 (n = 15) as a control group. PRNRP accounted for 3.05% (15/492) of all PRCC cases at our center. The median follow-up period was 41.3 months. All PRNRP cases were pT1N0M0, and only one involved recurrence (1 year after surgery). IHC analysis showed diffuse staining of CK7, EMA, and GATA3 but weak or negative staining of CD10, CD117, p504s, and vimentin in the PRNRP samples and distinctive IHC features in the other three tumor types. KRAS mutation was detected in 4/10 PRNRP cases. Among the 40 most commonly mutated genes identified, 5 (BCLAF1, PDE4DIP, NCOR1, PARP4, and PABPC1) have actionable alterations. Our study supports the suggestion that PRNRP is an entity distinct from CCPRCC, OPRCC, and PRCC1.

Novel α-galactosidase A gene mutation in a Chinese Fabry disease family: A case report

BACKGROUND

Fabry disease (FD) is a rare X-linked lysosomal storage disease caused by a deficiency of the enzyme α-galactosidase A.

CASE SUMMARY

Herein, we analyzed a four-generation Chinese family. The proband is a 57-year-old woman who was diagnosed with left ventricular hypertrophy and atrial fibrillation 7 years ago. Echocardiography showed an end-diastolic diameter of the interventricular septum of 19.9 mm, left ventricular end-diastolic diameter of 63.1 mm, and moderate-to-severe mitral regurgitation. Cardiac magnetic resonance indicated an enlarged left heart and right atrium, decreased left ventricular systolic and diastolic function, a left ventricular ejection fraction of 20%, and thickening of the left ventricular septum. In March 2019, gene and enzyme activity tests confirmed the diagnosis of FD. Her son was diagnosed with FD after gene and enzyme activity assay, and was prescribed agalsidase-β for enzyme replacement therapy in July 2020. Two sisters of the proband were also diagnosed with FD by genetic testing. Both of them had a history of atrial fibrillation.

CONCLUSION

A novel mutation was identified in a Chinese family with FD, in which the male patient had a low level of enzyme activity, early-onset, and severe organ involvement. Comprehensive analysis of clinical phenotype genetic testing and enzyme activity testing helped in the diagnosis and treatment of this FD family.

Biallelic mutations in DCDC2 cause neonatal sclerosing cholangitis in a Chinese family

BACKGROUND

Neonatal sclerosing cholangitis (NSC) is a severe cholestatic liver disease, which often develops into end-stage liver disease in childhood and requires liver transplantation. Mutations in CLDN1 and DCDC2 are confirmed to be the main pathogenic mechanism of NSC.

METHODS

Whole exon sequencing (WES) was performed to find the possible disease-causing mutations of this family. The mutation was confirmed by Sanger sequencing, and large fragment copy number variation was confirmed by qPCR.

RESULTS

We found novel biallelic mutations c.[705-2A>G];[923_1023del] in the DCDC2 gene of the proband. The proband's father had the heterozygous mutation c.705-2A>G, and his mother had a heterozygous c.923_1023del. The proband's younger brother, who had similar clinical manifestations, was found the same biallelic mutations with the proband.

CONCLUSION

Novel biallelic mutations were identified in DCDC2 of this Chinese family, according to the American College of Medical Genetics and Genomics (ACMG) guidelines for interpretation of sequence variants, both mutations were classified as pathogenic, which might be the cause of NSC in this family.

[Clinical characteristics and whole exon sequence study of a Chinese family with autosomal dominant lateral temporal lobe epilepsy]

Objective: To explore the genetic characteristics in a Chinese family with autosomal dominant lateral temporal lobe epilepsy (ADLTE) and analyze the correlation between genotype and phenotype. Methods: The natural history, clinical data and peripheral blood sample were collected in all patients and two healthy members of this ADLTE family. Whole exon sequence (WES) analysis strategy was used to explore the underlying mutations. Possible causative genetic variation was further confirmed by direct PCR and Sanger sequencing. The genotype-phenotype features were compared with previously reported cases. Results: A novel pathogenetic LGI1 frameshift mutation p.T134fs was identified in this study. The clinical phenotype was different from reported. Conclusion: This study reports a pathogenic LGI1 mutation in a Chinese ADLTE family for the first time, which suggests that LGI1 is a new genetic abnormality of ADLTE in Chinese.

Detection of ESR1 mutations in plasma and tumors from metastatic breast cancer patients using next-generation sequencing

PURPOSE

Liquid biopsy using digital PCR (dPCR) has been widely used for the screening of ESR1 mutations, since they are frequently identified in the hotspot. However, dPCR is limited to the known mutations. Therefore, we aimed to analyze the utility of next-generation sequencing (NGS) to discover novel ESR1 mutations.

METHODS

Whole exon sequencing of the ESR1 gene using NGS was performed in 16 primary and 47 recurrent tumor samples and 38 plasma samples from hormone receptor-positive metastatic breast cancer patients. Functional analyses were then performed for the novel mutations we detected.

RESULTS

We identified no mutations in primary tumors and six mutations in five recurrent tumors, including three types of known mutations (Y537C, Y537N, and D538G) and two novel mutations (E279V and G557R). We also identified seven mutations in five plasma samples, including three types of known mutations (S463P, Y537S, and D538G) and one mutation not reported in COSMIC database (L536H). All nine patients with ESR1 mutations were treated with aromatase inhibitors (AIs) prior to sampling, and the mutations were frequently detected in patients who received AI treatments in the metastatic setting. Among the three novel mutations (E279V, L536H, and G557R), L536H, but not E279V and G557R, showed ligand-independent activity. All three mutant proteins showed nuclear localization and had no relation with non-genomic ER pathways.

CONCLUSIONS

Although the molecular mechanisms of the E279V and G557R mutations remain unclear, our data suggest the utility of NGS as a liquid biopsy for metastatic breast cancer patients and the potential to identify novel ESR1 mutations.