Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey**
Ege University Faculty of Medicine, Department of Pediatric Genetics, İzmir, Turkey
SHOX (Short Stature Homeobox) which is located at Xp22.33 is evolutionary well-conserved developmental gene expressed in osteogenic cells. SHOX is one of the suspected components of the short stature in Turner syndrome cases. Also functional homolog of SHOX gene is located at Y chromosome. Haploinsufficiency of genes on the X chromosome results in Turner syndrome.
Here, we present a 26-month-old female referred to genetic counseling because of short stature and developmental delay. Her height was 71 cm (<3 percentile), weight 9.5 kg (<3 percentile). She had frontal bossing, hypertelorism, and bilateral mesomelic short upper extremities. Her motor and mental developments were normal. Bone X-ray survey revealed a thickness of long bones and delayed bone age.
Karyotype showed an extra genomic material at the p arm of the X chromosome. We performed chromosomal microarray. Approximately 18 Mb gain at the short arm of chromosome 6 and 680 Kb deletion at the p arm of X chromosome were detected.
Three genes including SHOX were deleted from the involved region of X chromosome. A gain of 63 genes located at chromosome 6p was observed, which resulted in partial trisomy of 6p. Effects of partial trisomy 6p in our case is not clear, but the deleted SHOX is suspected to be the reason for short stature and delayed bone age.