Background: Turner syndrome (TS) is a common genetic disorder with an incidence of 1 in 2500 live births due to chromosomal errors resulting in monosomy for the X chromosome with or without mosaicism. Familial TS has been rarely reported. We report two families having TS.
Methods: We report 6 patients with TS who had been referred to the Endocrinology department and Pediatric department at Hedi Chaker hospital, Sfax, Tunisia. We performed biochemical analysis, imaging and cytogenetic analyses.
Results: We report two families having TS. In the first, 4 sisters belonging to a consanguineous family were diagnosed at the age of 14, 17, 31 and 43 years, for TS because of the short stature dysmorphic syndrome and delayed puberty. The cytogenetic analyses performed showed different karyotypes 45XO, 45XO/46XX and two had 45X/46XX/47XXX and mother's karyotype analysis revealed no chromosomal abnormality. The second family included monozygotic twins having the same formula 45X/46XX. Their mother karyotype was not analysed. They were diagnosed at the age of 1 year because they suffered from dysmorphic syndrome. They had stature delay and both of them are now under growth hormone treatment.
Conclusions: In familial TS, mothers can carry a mosaic TS with an abnormal X and have normal fertility. But in our cohort mother's karyotype analysis revealed no chromosomal abnormality. Reported cases in the literature revealed chromosomal abnormality including mosaicism, presenting genetic defects which predisposed to chromosomal fragility and then chromosomal aneuploidy which can be hereditarily transmitted to the descendants. Thus, specific maternal karyotype should be taken into account in genetic counselling regarding potential risks for offspring. These cases suggest that a risk of recurrence is possible. And because of the clinical implications, TS families should be studied to exclude familial transmission.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology