A Novel Dominant Mesomelic Dysplasia Associated with A 1.0-Mb Microduplication of HOXD Gene Cluster at 2q31.1

A three-generation family with four patients affected by a mesomelic dysplasia was investigated for genome-wide DNA copy number variation profiles. This revealed a microduplication of a 1.0-Mb chromosomal segment at 2q31.1 spanning nine Homeo box D (HOXD) genes that co-segregated with the phenotype. Quantitative PCR analysis of a gene within this duplicated region showed consistent results. A phenotypically similar condition, mesomelic dysplasia Kantaputra type (MDKa; MIM 156232)[1], has also been mapped to this chromosomal region[2], raising the possibility that MDKa and the condition observed in this family may be allelic. three-generation family including four affected individuals and two unaffected individuals