Perinatology.  2023 Jun;34(2):99-104. 10.14734/PN.2023.34.2.99.

Mirror Hands and Feet with Ulnar Dimelia of Twin Pregnancy: Detection of a De Novo Duplication on Chromosome 2q35 Involving the Indian Hedgehog Locus

• Kim WJ
• Yoon S
• Heo WY
• Lee S
• Jang JH
• Sung JH
• Oh Sy

• KMID: 2544102
• DOI: http://doi.org/10.14734/PN.2023.34.2.99

Abstract

Mirror-image polydactyly, an extremely rare variant characterized by recognizable anteroposterior symmetry, is often comorbid with ulnar or fibular duplication (dimelia). Herein, we describe a case of twin pregnancy with fetal mirror hands and feet, increased nuchal translucency, cystic hygroma, and ulnar dimelia in both twins. Amniocentesis revealed normal karyotypes. The pregnancy was termi­nated at 18 weeks. Whole-exome sequencing and chromosomal microarray of the cord blood identi­fied a 1.345 millon base pairs (Mbp) duplication on chromosome 2q35 containing 36 OMIM genes, including the Indian hedgehog locus. This copy number variation was similar to that linked to acrocallosal-like syndrome characterized by extensive polysyndactyly and craniofacial abnormalities. A de novo duplication including the Indian hedgehog locus on chromosome 2q35 was detected through chromosomal microarray in a twin pregnancy with mirror hands and feet, suggesting that copy number variation involving the Indian hedgehog gene on chromosome 2q was the cause of polydactyly with ulnar dimelia.

Keyword

Microarray analysis; Mirror-image polydactyly; Prenatal diagnosis; Ulnar dimelia; Ultraso nography