Turner syndrome (TS) is defined by total or partial loss of the sex chromosomes X. Features vary widely including short stature and ovarian failure inconstantly associated with characteristic face, skeletal malformations, renal and cardiac anomalies and endocrine disorders.
We analyzed the clinical and cytogenetic profiles of 37 TS children diagnosed with TS from January 2007 to December 2011 in the aim to establish genotype- phenotype correlations.
Growth delay and hypothyroidism were noted respectively in 89.2% and 19.4%of patients. Diabetes and celiac disease was observed in 5.6% of cases. 35% of our cohort had a 45, X karyotype, 8.1% had 45, X/47, XXX mosaïcism and 5.4% have 45, X/46, XY mosaïcism Interestingly, FISH revealed the presence of SRY gene. The remainders had structural abnormalities: 35.1% had isochromosome Xq which was homogenous in roughly half of cases. 10.8% were diagnosed with a terminal deletion Xp and 5.4% with a ring of chromosome X.
There was no correlation between genotypes and clinical features. The short stature in girls with TS is thought to be related to the haploinsufficiency of the SHOX gene on Xp22.3. As a result, treatment with GH is now routinely adopted even if the GH hormone is normally secreted. The higher risk of autoimmune diseases in women with TS could result from haploinsufficiency of the FOXP3 gene on Xp 11.23.
Otherwise, we highlight the importance of detection of 45, X/46, Xy mosaïcism which may be cryptic requiring SRY probe FISH screening a condition that exposes to gonadoblastome and special chirurgical preventive treatment.