• Journal of Genetic Medicine
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• v.13 no.1
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• pp.46-50
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• 2016

Achondroplasia and hypochondroplasia are the two most common forms of short-limb dwarfism. They are autosomal dominant diseases that are characterized by a rhizomelic shortening of the limbs, large head with frontal bossing, hypoplasia of the mid-face, genu varum and trident hands. Mutations in the fibroblast growth factor receptor-3 (FGFR3) gene, which is located on chromosome 4p16.3, have been reported to cause achondroplasia and hypochondroplasia. More than 98% of achondroplasia cases are caused by the G380R mutation (c.1138G>A or c.1138G>C). In contrast, the N540K mutation (c.1620C>A) is detected in 60-65% of hypochondroplasia cases. Tests for common mutations are often unable to detect the mutation in patients with a clinical diagnosis of hypochondroplasia. In this study, we presented a case of familial hypochondroplasia with a rare mutation in FGFR3 identified by next generation sequencing.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.1
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• pp.42-46
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• 2013

Hypochondroplasia (HCH) is an autosomal dominant inherited skeletal dysplasia, usually caused by a heterozygous mutation in the fibroblast growth factor receptor 3 gene (FGFR3). A 27-year-old HCH woman with a history of two consecutive abortions of HCH-affected fetuses visited our clinic for preimplantation genetic diagnosis (PGD). We confirmed the mutation in the proband (FGFR3:c.1620C>A, p.N540K), and established a nested allele-specific PCR and sequence analysis for PGD using single lymphocyte cells. We performed this molecular genetic analysis to detect the presence of mutation among 20 blastomeres from 18 different embryos, and selected 9 embryos with the wild-type sequence (FGFR3:c.1620C). A successful pregnancy was achieved through a frozen-thawed cycle and resulted in the full-term birth of a normal neonate. To the best of our knowledge, this is the first report of a successful pregnancy and birth using single-cell allele-specific PCR and sequencing for PGD in an HCH patient.