Analysis of a child with Marfan syndrome due to a novel variant of FBN1 gene / 中华医学遗传学杂志

OBJECTIVE@#To carry out genetic testing for a child with Marfan syndrome (MFS) and explore its genotype-phenotype correlation.@*METHODS@#Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA and subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Functional impact of the variant was predicted by using bioinformatic software.@*RESULTS@#The child, a 13-year-old male, has featured Marfanoid habitus, with arm span exceeding his height, tapering fingers and toes, pectus excavatum and scoliosis, but absence of typical cardiovascular system diseases such as aortic dilation, thoracic-abdominal aortic aneurysm, mitral valve prolapse, and lens dislocation. The child has harbored a novel splice site variant c.7383_7413del (p. N2461Kfs*211) of the FBN1 gene, which was not found in his parents and younger brother. The variant was unreported previously.@*CONCLUSION@#The novel variant of p. N2461Kfs*211 of the FBN1 gene probably underlay the MFS in this child. Above finding has enriched the genotypic and phenotypic spectrum of MFS.

Diagnosis of one case of Williams-Beuren syndrome presenting with hypothyroidism by low-coverage massively parallel CNV sequencing / 中华内分泌代谢杂志

Objective@#To explore the clinical phenotypes and the genetic causes for a 5 years old boy with unexplained growth retardation, developmental delay, special face, and hypothyroidism.@*Methods@#Routine G-banding was performed to analyze the karyotype of the patient and his parents. In addition, whole exome sequencing and low-coverage massively parallel CNV sequencing (CNV-seq) were used to determine the potentially pathogenic variants as well as the copy number variations (CNVs).@*Results@#The child′s karyotype was 46, XY, and his parents′ karyotypes were normal.However, CNV-seq identified a heterozygous deletion of 1.56 Mb on chromosome region 7q11.23 in the patient, including 24 protein-coding genes, which were associated with Williams-Beuren syndrome. His parents′ results of CNV-seq were normal, indicating a de novo CNVs.@*Conclusion@#A Williams-Beuren syndrome child presenting with hypothyroidism was diagnosed by CNV-seq, which would contribute to further understanding the clinical phenotypes and pathogenesis of this disease.

Diagnosis of one case of Williams-Beuren syndrome presenting with hypothyroidism by low-coverage massively parallel CNV sequencing / 中华内分泌代谢杂志

Objective:To explore the clinical phenotypes and the genetic causes for a 5 years old boy with unexplained growth retardation, developmental delay, special face, and hypothyroidism.Methods:Routine G-banding was performed to analyze the karyotype of the patient and his parents. In addition, whole exome sequencing and low-coverage massively parallel CNV sequencing (CNV-seq) were used to determine the potentially pathogenic variants as well as the copy number variations (CNVs).Results:The child′s karyotype was 46, XY, and his parents′ karyotypes were normal.However, CNV-seq identified a heterozygous deletion of 1.56 Mb on chromosome region 7q11.23 in the patient, including 24 protein-coding genes, which were associated with Williams-Beuren syndrome. His parents′ results of CNV-seq were normal, indicating a de novo CNVs. Conclusion:A Williams-Beuren syndrome child presenting with hypothyroidism was diagnosed by CNV-seq, which would contribute to further understanding the clinical phenotypes and pathogenesis of this disease.

Multiple endocrine neoplasia-IIb with RET gene mutation p.M918T： A case report / 中南大学学报(医学版)

Multiple endocrine neoplasia-IIb (MEN-IIb) is a rare hereditary autosomal dominant syndrome caused by mutations in the RET proto-oncogene. It's characterized by medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), mucosal neuromas, and Marfanoid habitus. Because of the rarity of MEN-IIb and finiteness of clinical cognition, the majority of the patients suffer a delayed diagnosis. A MEN-IIb patient with the lingual mucosal neuromas since childhood was admitted in the Third Xiangya Hospital of Central South University in November, 2018. He had surgical history of mitral valve prolapse and spinal deformity. He was diagnosed with MTC and PHEO at the age of 22 and 28, respectively, and received surgical treatments. Sequencing of RET gene revealed a de novo heterozygous p.M918T mutation in the patient. Being aware of the unique clinical phenotype and screening of RET gene mutation may lead to the early diagnosis and better long-term outcome for MEN-IIb.