后轴多指畸形是一种常见的先天性畸形,涉及复杂的遗传因素。这项回顾性研究分析了诊断为四肢后轴多指的中国胎儿的细胞遗传学和分子学结果。胎儿核型分析和染色体微阵列分析(CMA)未发现任何异常,而三基因组全外显子组测序(trio-WES)鉴定出平滑(SMO)和(NM_005631.5:c.1219C>G,NP_005622.1:p.Pro407Ala,和NM_005631.5:c.1619C>T,NP_005622.1:p.Ala540Val)。Sanger测序验证了这些变体。突变在多个物种中是高度保守的。深入的生物信息学分析和家族性共分离表明,复合杂合变体可能是该胎儿后轴多指的原因。我们的发现为遗传咨询提供了基础,并将有助于更好地理解后轴多指的复杂遗传机制。
Postaxial polydactyly is a common congenital malformation which involves complex genetic factors. This retrospective study analyzed the cytogenetic and molecular results of a Chinese fetus diagnosed with postaxial polydactyly of all four limbs. Fetal karyotyping and chromosomal microarray analysis (CMA) did not find any abnormality while trio whole-exome sequencing (trio-WES) identified bi-allelic variants in
smoothened (SMO) and (NM_005631.5: c.1219C > G, NP_005622.1: p. Pro407Ala, and NM_005631.5: c.1619C > T, NP_005622.1: p. Ala540Val). Sanger sequencing validated these variants. The mutations are highly conserved across multiple species. In-depth bioinformatics analysis and familial co-segregation implied the compound heterozygous variants as the likely cause of postaxial polydactyly in this fetus. Our findings provided the basis for genetic counseling and will contribute to a better understanding of the complex genetic mechanism that underlies postaxial polydactyly.