Table_2_Case Report: A de novo Variant in NALCN Associated With CLIFAHDD Syndrome in a Chinese Infant.DOCX

BackgroundThe NALCN encodes a sodium ion leak channel that regulates nerve-resting conductance and excitability. NALCN variants are associated with two neurodevelopmental disorders, one is CLIFAHDD (autosomal dominant congenital contractures of the limbs and face, hypotonia, and developmental delay, OMIM #616266) and another is IHPRF (infantile hypotonia with psychomotor retardation, and characteristic facies 1, OMIM #615419).Case PresentationIn the current study, a Chinese infant that manifested abnormal facial features, adducted thumbs, and neurodevelopmental retardation was diagnosed with CLIFAHDD syndrome. A trio-based whole-exome sequencing revealed that the infant harbored a de novo variant of the NALCN gene (c.4300A>G, p.I1434V).ConclusionsOur findings further enriched the variant spectrum of the NALCN gene and may expand the clinical range of NALCN-related disorders.

背景：NALCN 编码一种调节神经静息传导和兴奋性的钠离子漏通道。NALCN 基因变异与两种神经发育障碍相关，其一为 CLIFAHDD（肢体和面部先天性挛缩、肌张力低下及发育迟缓，OMIM #616266），另一为 IHPRF（婴儿期肌张力低下伴精神运动迟滞，及特征性面容 1，OMIM #615419）。病例报告：在本研究中，一位中国婴儿表现出异常的面部特征、拇指内收和神经发育迟缓，被诊断为 CLIFAHDD 综合征。基于三联体的全外显子测序揭示了该婴儿携带 NALCN 基因的新发变异（c.4300A>G，p.I1434V）。结论：我们的发现进一步丰富了 NALCN 基因的变异谱，并可能扩大 NALCN 相关疾病的临床范围。