Background: Short stature occurs in Trisomy 21 but it is relatively slight during childhood. Turner syndrome would contribute significantly to short stature but the combined occurrence of both syndromes, even Turner mosaicism is unusual and could result in significant short stature.
Case: SP was referred for a growth assessment at 2.5 years. Her parents were counselled about short stature occurring in both syndromes but were worried that her height was significantly short even for either syndromes. Her height was 75.5 cm (HtSDS −3.6 non Turner, HtSDS −1.8 Turner, <5th centile Downs), weight 9.26 kg (10th centile Downs). Facial features were consistent with Downs syndrome. The only Turner features were hyper convex nails. Her height velocity was noted to fall to 3.5 cm/year by 2.8 years, with height now at 76.8 cm (HtSDS −4 non Turner, HtSDS −2.1 Turner), further away from the lowest centile of the Downs syndrome growth chart. The decision was made for a trial of growth hormone treatment and Turner doses with close monitoring of her IGF1 levels. She has now been on treatment for over 5 years. Auxology, IGF1 levels, GH dose are in the Table.
Investigations: Pre-treatment IGF1 171 ng/ml (51303), TSH 1.79 mU/l (0.44) fT4 9.8 pmol/l (6.314). Coeliac screen, Thyroid peroxidase antibodies negative. Renal ultrasound is normal. No cardiac lesions on echocardiogram. IGf1 11 months into treatment was 327 ng/ml (49289), her GH dose was reduced when levels increased further.
Conclusion: Growth data over 5 years is presented, dose titration during pubertal induction would be most challenging.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology