Infantile Sotos Syndrome: A Case Presenting with Mental Retardation and Overgrowth
Ibrahim Ozgun1
, Gülçin Arslan1, Bumin Nuri Dündar2
1Izmir City Hospital, Department of Pediatric Endocrinology, Izmir, Türkiye
2Izmir Katip Celebi University Hospital, Department of Pediatric Endocrinology and Metabolism, İzmir, Türkiye
Keywords: Overgrowth, Dysmorphic face, İntellectual disability, NSD1 mutation.
Abstract
Sotos syndrome is a growth disorder characterized by distinctive facial features, advanced bone age, macrocephaly, congenital visceral malformations, developmental delay, and epilepsy. Its estimated incidence is 1/14,000, making it one of the most common overgrowth syndromes. In this case report, we aim to present an 8-month-old female infant who was admitted to our clinic with a diagnosis of overgrowth and Sotos syndrome.
The patient's prenatal period was uneventful, and the parents were cousins in a consanguineous marriage. Physical examination showed body weight at the 99.8th percentile, height at the 99.9th percentile, and head circumference at the 98.4th percentile. He had generalized hypotonia, hypertelorism, prominent forehead, depressed nasal bridge, retrognathia, high palate, and brisk deep tendon reflexes. Bone age was advanced, consistent with 18-20 months, and cranial magnetic resonance imaging (MRI) was normal. Clinical findings and anthropometric measurements suggested Sotos syndrome. Although other overgrowth syndromes such as Marfan syndrome, homocystinuria, Beckwith-Wiedemann syndrome, Weaver syndrome, and Fragile X syndrome were considered, they were deemed less likely due to the lack of typical features and presence of prominent neuropsychiatric findings. Genetic analysis identified a heterozygous NSD1 mutation.
This case report highlights the importance of considering Sotos syndrome in the differential diagnosis of infants presenting with advanced anthropometric measurements for age, acromegaly-like somatic features, and neurodevelopmental delay.
Cite this article as: Ozgun I, Arslan G, Dündar BN. Infantile Sotos syndrome: a case presenting with mental retardation and overgrowth. Pediatr Acad Case Rep. 2026;5(2):52-5.
The parents’ of this patient consent was obtained for this study.
The authors declared no conflicts of interest with respect to authorship and/or publication of the article.
The authors received no financial support for the research and/or publication of this article.