Endocrine Abstracts

Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are distinct neurogenetic disorders involving the imprinting mechanism at 15q11–13 region. We report on 4 years and 9 months old boy who was referred to our laboratory in order to investigate a clinical bilateral cryptorquidy. The patient was born to non-consanguineous and healthy biological parents. Informed consent for publication was obtained from the parents. After normal pregnancy, the patient was delivered by caesarean section at full term, with a birth weight of 2600 g, but his height and head circumference were unknown. When he was born, he presented bilateral cryptorquidy and also he showed feeding problems. His development progress was delayed. He walked and developed speech at 3 years old. When he was examined at the age of 4 years, his head circumference was 50 cm, height 1.05 cm and weight 41 kg. Fluorescence in situ hybridisation using probes for SNRPN and D15521 loci, which map inside the chromosomal region 15q11–15q13 deletion or disomy of only maternal pattern. Methylation analysis at SNRPN showed an alpha axon, which carried out by Southern blot analysis revealed an abnormal only maternal methylation pattern. Microsatellites analysis of the patient showed the presence of only one region in three heterozygous loci inside the 15q11–13 region. The main PWS typical fractures’ in our patient are hyperfagia with obesity, mental deficiency and bilateral cryptorquidy. The predominant genetic defects in PWS are 15q11–13 deletions of paternal origin or only maternal chromosome disomy. In contrast to that, AS occurs in the presence of maternal deletions or paternal chromosome 15 uniparenteral disomy. In conclusion, we report this case with the objective of reinforce the necessity of analysis DNA methylation within the 15q11–13 region, which is an important tool for the correct diagnosis among children who presents with mental deficiency, bilateral cryptorquidy and obesity.