[Phenotypic and genetic characteristics of a child with 7p15 deletion syndrome].

OBJECTIVE

To explore the genetic basis for a child with multiple malformation and growth retardation.

METHODS

The child was subjected to low-coverage massively parallel copy number variation sequencing (CNV-seq) based on next generation sequencing (NGS) technique.

RESULTS

G-banding karyotyping analysis has found no abnormality in the boy and his parents. CNV-seq analysis discovered that the child has carried a heterozygous 4.36 Mb deletion (24 020 000-28 380 000) at 7p15.3p15.1. The same deletion was not found in either parent. The deletion has encompassed 28 OMIM genes including HOXA13, CYCS, DFNA5, HOXA11 and HOXA2. Among these, HOXA13 has been associated with distal limb deformity, hypospadias and cryptorchidism. HOXA1, HOXA3 and HOXA4 are involved in the formation of cardiac primordia and primordial tube, and HOXA2 is involved in the development of auditory system. The clinical phenotype of the child was consistent with that of 7p15 deletion syndrome.

CONCLUSION

Haploinsufficiency of HOXA1, HOXA2, HOXA3, HOXA4 and HOXA13 genes may underlie the clinical phenotype of the child, which is comparable to 7p15 deletion syndrome.