[Genetic analysis of three families affected with split-hand/split-foot malformation].

OBJECTIVE

To explore the genetic etiology of three families affected with split-hand/split-foot malformation (SHFM).

METHODS

Peripheral venous blood samples from 21 members of pedigree 1, 2 members of pedigree 2, and 2 members of pedigree 3 were collected. PCR-Sanger sequencing, microarray chip, fluorescence in situ hybridization (FISH), real-time PCR, and next-generation sequencing were employed to screen the mutations in the 3 families. The effect of the identified mutations on the finger (toe) abnormality were also explored.

RESULTS

Microarray and real-time PCR analysis has identified a duplication in all patients from pedigrees 1 and 3, which have spanned FKSG40, TLX1, LBX1, BTRC, POLL and FBXW4 (exons 6-9) and LBX1, BTRC, POLL and FBXW4 (exons 6-9) genes, respectively. A missense mutation of the TP63 gene, namely c.692A>G (p.Tyr231Cys), was found in two patients from pedigree 2. FISH analysis of chromosome 10 showed that the rearrangement could fita tandem duplication model. However, next-generation sequencing did not identify the breakpoint.

CONCLUSION

The genetic etiology for three families affected with SHFM have been identified, which has provideda basis for genetic counseling and guidance for reproduction.