Background: Prader Willi Syndrome (PWS) is a rare genetic disorder with a wide range of symptoms manifestation. Main characteristics are hypotonia, growth retardation, feeding difficulties in neonatal period, increased appetite and obesity in childhood, delayed puberty or hypogonadism in adolescence. It is also associated with behavioral disturbances and impaired cognitive function. The genetic defect is located on the 15q11-13 chromosome.
Objective and hypotheses: A 7 years old girl with PWS, admitted to our unit for the regular follow up due to growth hormone treatment. She was diagnosed at the age of 2 months. Her genetic test showed deletion of paternal 15q11-13 and presence of one maternal allele on the D15S10, Gabrb3 and D15S113.
Method: Physical examination revealed bilateral thelarche and pubarche (Tanner stage: B2A1P2M0). Her height was 118.7 cm (−0.47SDS), her weight was 27 kg (1.7 SDS) and her BMI was 19.16 kg/m2 (1.68 SDS). GnRH test result was indicative for puberty (peak LH:17.4 mIU/ml, peak FSH:13.4 mIU/ml).
Results: The patient didnt follow puberty suppression treatment as the thelarche was spontaneously regressed. In the next 6 months thelarche relapsed, increased growth rate was noted and the laboratory tests revealed augmented LH, FSH and Estradiol levels. On the physical examination, height was 127.6 cm (0.06 SDS), weight was 36 kg (3.4 SDS) and BMI was 22.32 kg/m2 (2.25 SDS). She was put on GnRH analogue treatment.
Conclusion: The most common pubertal disorders of the PWS are delayed or incomplete puberty. In our case the patient presented with incomplete precocious puberty but later progressed to complete precocious puberty. There is a very limited amount of information in the literature concerning association of precocious puberty with PWS (<4%), probably due to deletion of specific genes on the affected part of the chromosome. Recently MKRN3 gene mutation, which is located on the affected part of the causative chromosome, has been correlated with precocious puberty in patients with PWS.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology