Idris Mohammed1,2, Sara Al-Khawaga1,2, David Bohanna3, Abdusamea Shabani4, Faiyaz Khan2, Donald R Love3, Zafar Nawaz5, Khalid Hussain2. 1. College of Health & Life Sciences, Hamad Bin Khalifa University, Doha, Qatar. 2. Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, Doha, Qatar. 3. Department of Radiology, Sidra Medicine, Doha, Qatar. 4. Division of Pathology Genetics, Department of Pathology, Sidra Medicine, Doha, Qatar. 5. Diagnostic Genomic Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Abstract
BACKGROUND: There are few reports describing the proximal deletions of the short arm of chromosome 20, making it difficult to predict the likely consequences of these deletions. Most previously reported cases have described the association of 20p11.2 deletions with Alagille syndrome, while there are others that include phenotypes such as panhypopituitarism, craniofacial dysmorphism, polysplenia, autism, and Hirschsprung disease. METHODS: Molecular karyotyping, cytogenetics, and DNA sequencing were undertaken in a child to study the genetic basis of a complex phenotype consisting of craniofacial dysmorphism, ocular abnormalities, ectopic inguinal testes, polysplenia, growth hormone deficiency, central hypothyroidism, and gastrointestinal system anomalies. RESULTS: We report the smallest described de novo proximal 20p11.2 deletion, which deletes only the FOXA2 leading to the above complex phenotype. CONCLUSIONS: Haploinsufficiency of the FOXA2 only gene is associated with a multisystem disorder.
BACKGROUND: There are few reports describing the proximal deletions of the short arm of chromosome 20, making it difficult to predict the likely consequences of these deletions. Most previously reported cases have described the association of 20p11.2 deletions with Alagille syndrome, while there are others that include phenotypes such as panhypopituitarism, craniofacial dysmorphism, polysplenia, autism, and Hirschsprung disease. METHODS: Molecular karyotyping, cytogenetics, and DNA sequencing were undertaken in a child to study the genetic basis of a complex phenotype consisting of craniofacial dysmorphism, ocular abnormalities, ectopic inguinal testes, polysplenia, growth hormone deficiency, central hypothyroidism, and gastrointestinal system anomalies. RESULTS: We report the smallest described de novo proximal 20p11.2 deletion, which deletes only the FOXA2 leading to the above complex phenotype. CONCLUSIONS:Haploinsufficiency of the FOXA2 only gene is associated with a multisystem disorder.