Abstract
Short stature homeobox-containing gene (SHOX) haploinsufficiency is an important genetic cause of short statue associated with well recognised dysmorfic signs. SHOX is localised in pseudoautosomal region 1 (PAR 1) of both sex chomosomes (Xp22.3, Yp11.3).
Because genes in PAR 1 do not undergo X inactivation, healthy individuals express two copies of SHOX. SHOX gene encodes a homeodomaine transcription factor expressed during early fetal life in developing skeletal tissue.
SHOX deficiency (due to deletion or point mutation) is present in 2,4% individuals with short stature (<2,0 SDS). SHOX deficient patients have variable degrees of growth impairment with or without a spectrum of skeletal abnormalities (Madelung deformity, shortening of the middle segments of upper and lower limbs and bowing of forearms consistent with dyschondrosteosis, short metatarsal and metacarpals and arch palate).
SHOX deficiency includes a continuum of clinical conditions spanning from severe Langer syndrome (homozygous SHOX mut