SAT-055 A De Novo 1p13.2 Deletion Related to Short Stature, Hypothyroidism and Mild Developmental Delay

Background: Chromosomal deletions may lead to variable phenotypic alterations, depending on which loci and genes are deleted. We present the case of a boy with a de novo 1p13.2 deletion which was diagnosed by array-CGH analysis. Clinical Case: A Greek boy, who was referred for evaluation of growth failure, was investigated. He was delivered at term by cesarean section, with normal birth weight (3.060 kg), birth length (51 cm) and head circumference (35.5 cm). There was no positive family history for short stature. Target height was on the 25(th) percentile. He presented with growth deceleration since the age of 12 months leading to stature lower than the 3(rd) percentile at the age of two years, while his weight was at the 3(rd) percentile. Macrocephaly was appreciated (53 cm, >95(th) percentile). Dysmorphic facial features resembling Noonan syndrome, such as frontal bossing, depressed nasal bridge and low-set ears were recognized. His motor development was normal. Laboratory examination revealed hypothyroidism and treatment with L-thyroxine was initiated. He had regular follow-ups at 6 months intervals. A mild delay in speech development and motor skills was appreciated. At the age of five years old, as his growth rate remained slow, growth hormone (GH) stimulation tests were performed. GH had a borderline normal peak of 9.9 ng/ml. IGF-1 levels were also within normal range (123.7 ng/ml). Magnetic Resonance Imaging (MRI) of the pituitary gland and the brain was normal. Array-CGH analysis detected a loss of approximately 800 Kb on chromosome 1p13.2; these alterations affect 8 genes in the OMIM database. The deleted segment was mapped at chr1: 115,186,092_115,977,647 region. The genomic coordinates are listed according to genomic build GRCh37/hg19. The genetic material analysis did not show the presence of a deficit in chromosomal region 1p13.2 (chr1: 115,186,092_115,977,647) in neither of the parents, indicating that this finding was created de novo. Conclusion: We describe a patient with a Noonan like phenotype, due to a 1p13.2 deletion. In the international literature and databases of Database of Genomic Variants and Database of Chromosomal Imbalance and Phenotype in Humans Using Ensemble Resources there are no reports of normal individuals or patients with a similar finding in chromosomal region 1p13.2. Regular follow up of the patient is needed in order to better understand the evolution of the phenotype.