Chromosome 9p deletion syndrome. 9p minus syndrome. Monosomy 9p.
Incidence
Autosomal dominant (9p-). Very rare syndrome.
Clinical Characteristics
Chromosome 9, Partial Monosomy 9p is a rare chromosomal disorder in which there is deletion (monosomy) of a portion of the 9th chromosome. Characteristic symptoms and findings include mental retardation; distinctive malformations of the skull and facial (craniofacial) region, such as an abnormally shaped forehead (i.e., trigonocephaly), upwardly slanting eyelid folds (palpebral fissures), and unusually flat midfacial regions (midfacial hypoplasia); structural malformations of the heart (congenital heart defects); genital defects in affected males and females; and/or additional physical abnormalities. In most cases, Chromosome 9, Partial Monosomy 9p appears to result from spontaneous (de novo) errors very early in embryonic development that occur for unknown reasons (sporadically). In summary, it is related to a partial deletion of the short arm of chromosome 9 with mental retardation, craniofacial anomalies, abnormal dermatoglyphics, short and webbed neck, heart murmurs, square nails, and other defects. In addition to mental retardation, clinical features include delayed motor development, trigonocephaly, wide nasal bridge, large upper lip, high-arched palate, long fingers and toes due to elongation of the second phalanx, flat feet, and dermatoglyphic peculiarities.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype. Partial deletion of the short arm of chromosome 9.