ESPE Abstracts

Introduction: Angelman syndrome is caused by de novo maternal deletions in 15q11-q13 region of chromosome 15 in approximately 70% of affected children.

Patient and Methods: A two and a half year-old boy with hypotonia, absence of speech, low weight (-4.38 SDS) and short stature (-1.14 SDS) had pale skin and typical facial features with wide and prominent forehead, low-lying ears, wide mouth, small and widely spaced teeth. The boy was born small for gestational age (SGA) with birth weight (-2.0 SDS) and birth length (-1.09 SDS) in 39th gestational week (GW). He had an early onset of seizures treated and controlled by antiepileptic drugs.

Results: The IGF1, IGF BP3, thyroxine (T4) and anti-thyroid peroxidase antibody (anti TPO) serum concentrations were within reference range, but thyroid stimulating hormone (TSH- 14.5uIU/ml) level was elevated for his age and sex. Karyotype was 46, XY. An EEG revealed right-sided focus of slow waves. Multiplex ligation probe amplification (MLPA) and a methylation analysis (MS-MLPA) detected a deletion in 15q11-q13 region of chromosome 15 with minimal length of 3Mb and an absence of maternal allele. His TSH (7.3uIU/ml) serum concentration decreased and he grew by 3cm after two months of replacement treatment with Levothyroxine.

Conclusions: This is a description of two and a half year-old SGA born boy with two very rare associated conditions, an Angelman syndrome and hypothyroidism. The molecular analyses confirmed maternal origin of deletion in the critical region of chromosome 15.

Keywords: an Angelman syndrome, hypothyroidism, small for gestational age, MS-MLPA