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Biomedical subjects

Fu Xiong

Publications and source records attributed to Fu Xiong.

2 recordsLinked to original sources

Genetic analysis of partial duplication of the long arm of chromosome 16.

BACKGROUND: Pure partial trisomy 16q12.1q22.1 is a rare chromosome copy number variant (CNV). The primary clinical phenotypes associated with this syndrome include abnormal facial morphology, global developmental delay (GDD), short stature, and reported predisposing factors for atypical behavior, autism, the development of learning disabilities, and neuropsychiatric disorders. The dosage-sensitive genes associated with partial trisomy are not disclosed preventing to establish a genotype-phenotype correlation. METHODS: We report a case of a Chinese patient diagnosed with GDD and an abnormal facial shape, who was found to have partial trisomy 16 through karyotyping and high-throughput sequencing analysis. Karyotype and CNV tracing analyses were also conducted on the biological parents of the patient to assess for any chromosomal structural abnormalities. Additionally, we included 29 patients with pure partial trisomy 16q, reported in the DECIPHER database and the literature. We and performed a genotype-phenotype correlation analysis. RESULTS: The proband, a 2-year-old female, was found to have a de novo 21.96 Mb duplication located between 16q12.1q22.1, with no other deletions observed on other chromosomes, indicating a pure partial trisomy of 16q. Through genotype and phenotype analysis of 29 individuals, we found that patients with the duplicated region located at the distal region of 16q may exhibit more severe symptoms than those with duplication at the proximal region; however, no relationship was identified between phenotype and the size of the duplicated segment. CONCLUSION: We report, for the first time, a patient with partial trisomy 16q validated by multiple genetic tests, including CNV-seq, whole exome sequencing (WES), and karyotyping. It is speculated that partial trisomy of 16q may be associated with continuous gene duplication. However, functional studies are necessary to identify the causative gene or critical region linked to duplication syndrome of chromosome 16q.

Child, Preschool

Four novel mutations identified in the COL4A3, COL4A4 and COL4A5 genes in 10 families with Alport syndrome.

BACKGROUND: Alport syndrome (AS) is an inherited nephropathy caused by mutations in the type IV collagen genes. It is clinically characterized by damage to the eyes, ears and kidneys. Diagnosis of AS is hampered by its atypical clinical picture, particularly when the typical features, include persistent hematuria and microscopic changes in the glomerular basement membrane (GBM), are the only clinical manifestations in the patient. METHODS: We screened 10 families with suspected AS using whole exome sequencing (WES) and analyzed the harmfulness, conservation, and protein structure changes of mutated genes. In further, we performed in vitro functional analysis of two missense mutations in the COL4A5 gene (c.2359G > C, p.G787R and c.2605G > A, p.G869R). RESULTS: We identified 11 pathogenic variants in the type IV collagen genes (COL4A3, COL4A4 and COL4A5). These pathogenic variants include eight missense mutations, two nonsense mutations and one frameshift mutation. Notably, Family 2 had digenic mutations in the COL4A3 (p.G1170A) and UMOD genes (p.M229K). Family 3 had a digenic missense mutation (p.G997E) in COL4A3 and a frameshift mutation (p.P502L fs*151) in COL4A4. To our knowledge, four of the 11 mutations are novel mutations. In addition, we found that COL4A5 mutation relation mRNA levels were significantly decreased in HEK 293 T cell compared to control, while the cellular localization remained the same. CONCLUSIONS: Our research expands the spectrum of COL4A3-5 pathogenic variants, which is helpful for clinical and scientific research.

Humans