Deletion of SHANK3 and CREBBP gene in the patients with intellectual disability and mix phenotype

Abstract

Rubinstein-Taybi Syndrome (RSTS) as a group of congenital anomalies mainly include, short broad thumbs and toes, short stature and intellectual disability are caused by either a micro-deletion in the CREBBP (CBP) or EP300 genes. Generally most RSTS patients have a deletion in the CREBBP gene but some patients have shown deletion in the EP300 gene. Here we introduce an affected case without some typical characteristics of RSTS with deletions in the CREBBP and SHANK3 genes. The patient was a 24 years old man with a history of infantile hypotonia and childhood developmental delay, heavy eyebrows, ptosis, speech difficulty without large thumb and toes. The conventional cytogenetic finding was normal male. Further investigation was performed using Multiplex Ligation Probe Amplification (MLPA) technique to screen micro-deletion syndromes and subtelomeric rearrangements and Micro-deletion was detected in CREBBP and SHANK3 gene and a detected in DECR2 gene. Deletion in the CREBBP or EP300 genes or both in the patients with broad thumb and toes (RSTS) has been detected but there are other patients with deletion in CREBBP gene without this sign of RSTS. However, we report SHANK3 gene deletion in the patient with deletion in CREBBP gene and without broad thumbs and toes. Keywords: Rubinstein-Taybi Syndrome (RSTS); CREBBP; SHANK3; Broad thumb and toes