Monosomy 18p

Monosomy 18p describes a chromosomal disease in which a partial or complete deletion of the short arm of a chromosome 18 occurs. The most common form suffers from nonspecific and moderate dysmorphisms.

Two thirds of patients have a terminal, new-onset deletion, with the remaining cases presenting three distinct manifestations: (i) de novo translocation with loss of 18p, (ii) mis-segregation of a parental translocation or inversion, or (iii) a Ring chromosome 18.

Parental transmission of the syndrome has also been described.

The symptoms are very different and varied and have different degrees of development in each patient.