A SOX3 (Xq26.3-27.3) duplication in a boy with growth hormone deficiency, ocular dyspraxia, and intellectual disability: a long-term follow-up and literature review.

OBJECTIVE

SOX3 is located on the long arm of the X chromosome (Xq27.1) and both the under- and over-expression of this gene have been reported in cases of hypopituitarism with or without intellectual disabilities. Nevertheless, only a few cases have as yet been extensively described.

DESIGN

A 3-year 11 month-old male was brought in for growth failure (height -2.4 SDS). The patient was born at term of a second uneventful pregnancy by caesarean section for podalic presentation: the birth weight (0.1 SDS), length (0.4 SDS), and head circumference (-0.3SDS) were normal. Neurodevelopmental delays and ocular motor dyspraxia had been noted since 6 months of age. The endocrinological evaluation showed a very low IGF-I concentration (44 μg/L). The thyroid hormone level was normal and coeliac disease markers were negative. Bone age was considerably delayed. Target height was normal (0.5 SDS).

RESULTS

Growth hormone stimulation tests were compatible with a classic GHD, while a brain MRI disclosed a pituitary hypoplasia with ectopic neurohypophysis. rhGH treatment was then begun and the auxological follow-up showed a good response. At the age of 9 yrs, the height was 0.3 SDS, the weight was 0.1 SDS, and the pubertal evaluation was PH1 AH1 T2 ml bilaterally. Due to the presence of neuromotor delays and MRI abnormalities, a genetic evaluation was conducted and an array-CGH of the patient's DNA discovered an Xq26.3-27.3 duplication comprising the SOX3 gene.

CONCLUSIONS

SOX3 involvement should be considered in a male with short stature due to GH deficiency associated with intellectual disability.