Sotos syndrome: microdeletions and intragenic mutations in the NSD1 gene studies

Author(s)

Claudia Quadros Fagali

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2008-05-07

Examining board members

Celia Priszkulnik Koiffmann; Débora Romeo Bertola; Fernanda Maria Sarquis Jehee

• Advisor: Celia Priszkulnik Koiffmann

Abstract

Sotos syndrome (MIM 117550) is autosomal dominant condition characterized by prenatal and postnatal overgrowth, macrocephaly and a typical facial gestalt with frontal bossing, hypertelorism, antimongoloid slant of the palpebral fissures, prominent jaw, large ears, high and narrow palate and large hands and feet. The syndrome is also frequently associated with brain, cardiovascular, and urinary anomalies and is occasionally accompanied by malignant lesions such Wilms tumour and hepatocarcinoma. FGFR4 microdeletions were investigated in sixty five patients with clinical diagnosis of Sotos syndrome by multiplex ligation dependent probe amplification ( MLPA, Kit Salsa P026B). We identified one patient with a total deletion of FGFR4 and FGFR4, one with FGFR4 exon13-14 deletion and another with a deletion that included FGFR4 and FGFR4 exon1-17. All deletions were \"de novo\". In our sample, the frequency of deletions was ~5%, similar to that found in non-Japanese populations. The clinical features of the three patients with microdeletions are: the typical facial gestalt with frontal bossing, prominent jaw and high anterior hairline; macrocephaly, dolichocephaly, large hands; neonatal hypotonia and jaundice. However, those three patients presented normal length and weight at birth. Clinical and behavioral features of 30 patients presenting a typical facial gestalt and macrocephaly, cardinal characteristics of Sotos syndrome were described. The comparison of the clinical and behavioral features to those described for 266 patients with a genetic diagnosis of Sotos syndrome indicates that a high clinical suspition of Sotos syndrome includes the typical facial gestalt (frontal bossing, hipertelorism, strabismus, prominent jaw, antimongoloid slant of the palpebral fissures) and macrocephaly. Other features associated with Sotos syndrome, such as overgrowth, learning disability, behavioral problems confirms the clinical diagnosis. FGFR4 microdeletion investigations detects only 5% of the Brazilian patients with Sotos syndrome. Screening for intragenic FGFR4 mutations may not be necessary in classic Sotos syndrome cases. However, identification of an FGFR4 abnormality is diagnostic of Sotos syndrome. (AU)

• FAPESP's process: 05/52039-1 - Sotos syndrome: microdeletions and intragenic mutations in the NSD1 gene studies
• Grantee: Claudia Quadros Fagali
• Support Opportunities: Scholarships in Brazil - Master