Chromosome 8, Monosomy 8p is a rare chromosomal disorder characterized by deletion (monosomy) of a portion of the eighth chromosome. Associated symptoms and findings may vary greatly in range and severity from case to case. However, common features include growth deficiency; mental retardation; malformations of the skull and facial (craniofacial) region, such as a small head (microcephaly) and vertical skin folds that may cover the eyes' inner corners (epicanthal folds); heart (cardiac) abnormalities; and/or genital defects in affected males. Additional craniofacial features may also be present that tend to become less apparent with age, such as a short, broad nose; a low, wide nasal bridge; and/or a small jaw (micrognathia). In most cases, Chromosome 8, Monosomy 8p appears to result from spontaneous (de novo) errors very early in embryonic development that occur for unknown reasons.