BackgroundProximal symphalangism is a rare disease with multiple phenotypes including reduced proximal interphalangeal joint space, symphalangism of the 4th and/or 5th finger, as well as hearing loss. At present, at least two types of proximal symphalangism have been identified in the clinic. One is proximal symphalangism-1A (SYM1A), which is caused by genetic variants in Noggin (NOG), another is proximal symphalangism-1B (SYM1B), which is resulted from Growth Differentiation Factor 5 (GDF5) mutations.Case presentationHere, we reported a Chinese family with symphalangism of the 4th and/or 5th finger and moderate deafness. The proband was a 13-year-old girl with normal intelligence but symphalangism of the 4th finger in the left hand and moderate deafness. Hearing testing and inner ear CT scan suggested that the proband suffered from structural deafness. Family history investigation found that her father (II-3) and grandmother (I-2) also suffered from hearing loss and symphalangism. Target sequencing identified a novel heterozygous NOG mutation, c.690C > G/p.C230W, which was the genetic lesion of the affected family. Bioinformatics analysis and public databases filtering further confirmed the pathogenicity of the novel mutation. Furthermore, we assisted the family to deliver a baby girl who did not carry the mutation by genetic counseling and prenatal diagnosis using amniotic fluid DNA sequencing.ConclusionIn this study, we identified a novel NOG mutation (c.690C > G/p.C230W) by target sequencing and helped the family to deliver a baby who did not carry the mutation. Our study expanded the spectrum of NOG mutations and contributed to genetic diagnosis and counseling of families with SYM1A.

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Abstract. The aim of the present study was to investigate the mutation/variant of thyrotropin receptor (TSHR) and thyroid transcription factor-1 (TTF-1) genes in Chinese children with congenital hypothyroidism (CH). Seventy-nine and forty-nine Chinese children with CH were enrolled for molecular analysis of the TSHR gene and TTF-1 gene, respectively. One hundred normal children were evaluated as control. The coding regions of TSHR and TTF-1 genes were amplified by polymerase chain reaction and sequenced. Sequencing of the TSHR gene revealed a compound heterozygous variants (Pro52Thr/Val689Gly) and a heterozygous variant (Gly245Ser) in 2 of 79 patients. In 30 patients and 33 controls the normal cytosine at position 2181 in exon 10 of TSHR gene was replaced by a guanine， resulting in the replacement of Asp 727 by Glu. In 47 patients and 50 controls, the normal thymidine at position 561 in exon 7 of TSHR gene was replaced by a cytosine. This substitution did not change the amino acid in position 187. Sequencing of the TTF-1 gene revealed no mutation or polymorphism in 49 patients and 100 controls. In conclusion, three heterozygous variants (Pro52Thr, Gly245Ser, Val689Gly) of TSHR gene were firstly detected in Chinese children with CH. There were polymorphisms in exon 10 at nucleotide 2181 (C/G) and in exon 7 at nucleotide 561 (T/C) in TSHR gene. No mutation or polymorphism was detected in the coding region of TTF-1 gene. The mutation/variant of TSHR and TTF-1 genes is relatively rare in Chinese children with CH.

Objective: Pierson syndrome (OMIM 609049) is a rare autosomal recessive disorder characterized by congenital nephrotic syndrome and complex ocular abnormalities. Severe renal symptoms had be associated with truncating mutations. Few Chinese patients from diverse ethnic background had been evaluated and reported with this syndrome. Here we report the first Uyghur patient with typical Pierson syndrome phenotypes and a novel pathogenic homozygous variant in LAMB2 gene.Method: A thirty-nine-day old Uyghur girl was born to consanguineous parents, the girl presented with general edema, severe hypotonia and bilateral microcoria. Laboratory tests revealed severe proteinuria, microscopic haematuria, hypoalbuminaemia. By the age of 74 days, she died of renal failure and respiratory infection. We detected on mutations of LAMB2 gene by the sanger sequencing.Result:Sanger sequencing detected a homozygous 2-bp deletion (c.2044_2045insTT/p.Cys682Phefs*13) in the exon 16 of LAMB2 gene. Both parents are heterozygous carriers.Conclusion: We reported the first Uyghur case of LAMB2 gene homozygous mutation leading to severe phenotype Pierson syndrome. The clinical presentation of the patient and the novel pathogenic variant detected in this patient added to the overall knowledge of this rare condition.

ABSTRACT. Von Hippel-Lindau (VHL) syndrome is characterized by hemangioblastomas of the brain, spinal cord, and retina, renal cysts, clear cell renal cell carcinoma, and pheochromocytoma. VHL is caused by mutations in the VHL tumor suppressor gene. We attempted to detect mutation in the VHL gene in a 5-generation Chinese family with VHL. We identified a novel small duplication that altered the reading frame downstream and created a premature TGA stop signal, resulting in severely truncated pVHL30 (p.Gly114Serfs*50) and pVHL19 (p.Gly61Serfs*50). This change was predicted to be an elongin-binding domain deletion.