Abstract
The differential diagnosis of familial conditional growth disorders must also contemplate the transfer or pseudoautosomálně autosomal hereditary pathological talents. One is a relatively frequent insufficiency SHOX (Short stature HOmeoboXcontaining gene) gene, which is located in pseudoautosomální Region 1 (PAR 1) of the two sex chromosomes (Xp22.3, Yp11.3).
It is a regulatory gene encoding transcription factor formation, which plays an important role in the growth of long bones. SHOX is not subject to X inactivation and is under physiological conditions present in two functional copies.
Haploinsuficience SHOX (due to deletion or point mutation) occurs in 2.4% of subjects with short stature (<-2.0 SDS) and has been associated with numerous skeletal abnormalities: Madelung deformity of the forearm, reducing secondary segments of long bones (mesomelií), significant curvature radius and tibia, shorter metacarpals and metatarsal (especially IV.) and gothic palate. Bone deviations are more frequent and more pronounced in girls and their severity increases with age.
SHOX insufficiency involves a continuum of clinical entities with varying severity of symptoms: from serious disability in patients with Langerovým syndrome (homozygous SHOX defect), despite milder phenotype in Leri-Weillova syndrome to isolated growth retardation. SHOX deletions is also part of Turner syndrome, which was due in 1997 and identified a gene that has become the default model for growth hormone treatment.
Proven SHOX gene deficiency is currently one of the indications for the treatment of growth hormone in the Czech Republic.