Center for Human Genetics and Laboratory Diagnostics, Dr. Klein, Dr. Rost and Colleagues

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Microdeletion 1p36 [Q93]

OMIM number: 607872

Dr. med. Imma Rost

Scientific Background

With a frequency of 1:5,000 to 1:10,000, the microdeletion 1p36 is thought to be the most frequent terminal microdeletion. Most patients have a moderate or a severe developmental disorder with a strong impairment of expressive speech, muscular hypotonia as well as growth retardation. Physical features include: a large late-closing anterior fontanelle, deep-set eyes, straight eyebrows, broad nasal bridge, midface hypoplasia, low-set dysplastic ears, pointed chin, brachy- and camptodactyly and short feet. Some patients exhibit adipositas and hyperphagia. Approx. 70% present with a congenital heart defect, 23% with a noncompaction cardiomyopathy. Almost all patients have an abnormal EEG, slightly less than half also have seizures. Vision or eye problems and hearing loss occur in more than half of all patients as well.

The microdeletion 1p36 is usually detected by subtelomere screening or increasingly with array CGH; in individual cases it can be detected under the microscope with high-resolution banding techniques (between 600 and 1,000 bands) in chromosome analysis.