Congenital hemidysplasia with ichthyosiform erythroderma and limb defects also known as CHILD syndrome is an X-linked dominant, male lethal genodermatosis with a prevalence of 1 in 100,000 live births. Mutations in NSDHL gene located at Xq28 potentially impair the function of NAD(P) H steroid dehydrogenase-like protein and is responsible for its pathogenesis. The proband was a 9-month-old twin (T2) girl with a healthy twin sister (T1) of Sri Lankan origin born to non-consanguineous parents. She presented with right sided continuous icthyosiform erythroderma and ipsilateral limb defects and congenital hemidysplasia since birth. Notably the child had ipsilateral hand hypoplasia and syndactyly. There were other visceral abnormalities. We performed whole exome sequencing and found a novel heterozygous variant (NSDHL, c.713C > A, p.Thr238Asn). We report a novel missense variant in the NSDHL gene that resides in a highly-conserved region. This variant affects the NAD(P) H steroid dehydrogenase-like protein function via reduction in the number of active sites resulting in the CHILD syndrome phenotype and syndactyly.

中文翻译：

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NSDHL基因的新变异与CHILD综合征和综合征相关-病例报告。

先天性子宫增生伴鱼鳞状红皮病和肢体缺损也称为CHILD综合征，是X连锁的显性男性致死性皮肤病，发病率为100,000例活产儿中的1例。位于Xq28的NSDHL基因中的突变可能损害NAD（P）H类固醇脱氢酶样蛋白的功能，并对其发病机理负责。先证者是一个9个月大的双胞胎（T2）女孩，有一个健康的斯里兰卡双胞胎姐妹（T1），由非血缘父母生。自出生以来，她出现了右侧连续性甲状腺球状红皮病和同侧肢体缺损以及先天性异型增生。值得注意的是，该孩子患有同侧手发育不全和综合征。还有其他内脏异常。我们进行了完整的外显子组测序，发现了一个新的杂合变异体（NSDHL，c.713C> A，p.Thr238Asn）。我们报告了位于高度保守区域的NSDHL基因中的新型错义变异。此变体通过减少导致CHILD综合征表型和综合征的活动位点的数量来影响NAD（P）H类固醇脱氢酶样蛋白的功能。