Chromosome 1q41-Q42 Deletion Syndrome

Chromosome 1q41-q42 deletion syndrome is characterized by a small, but variable deletion in a particular place on the long arm of one copy of chromosome 1, usually spanning several genes. There have been variable features described in the literature, and individuals have ranged from being mildly to severely affected. Features may include poor feeding in infancy; developmental delay including delayed or absent speech; and moderate to severe intellectual disability. Other features may include hypotonia; short stature; seizures; heart defects; structural brain anomalies (most commonly underdevelopment of the corpus callosum); genitourinary abnormalities; cleft palate; microcephaly; vision problems; hearing loss; and other abnormalities. Some may have characteristic facial features. Researchers have suggested the features are caused by disruption of at least four genes.