The 13q deletion syndrome follows partial or complete deletion in part of the long arm of chromosome 13. The severity of the syndrome depends on the location and extent of the deletion.


Clinical features:

(1) intrauterine growth retardation, with reduced growth after birth

(2) microcephaly, often with trigonocephaly and holoprosencephaly

(3) mental deficiency


Facial findings:

(1) high, prominent nasal bridge with hypertelorism

(2) epicanthal fold

(3) ptosis

(4) microphthalmia

(5) colobomata

(6) metopic bridge (may be related to trigonocephaly

(7) prominent maxilla

(8) micrognathia

(9) prominent ears that are low lying and slanting

(10) short, webbed neck


Changes in the extremities:

(1) thumb hypoplasia or aplasia

(2) clinodactyly in fifth finger (medial or lateral deviation)

(3) fusion of 4th and 5th metacarpals

(4) talipes equinovarus

(5) hypoplasia of great toe


Other findings:

(1) cardiac malformations

(2) focal agenesis of lumbar vertebrae

(3) in males, hypospadias, bifid scrotum or cryptochordism

(4) renal anomaly

(5) increased risk of retinoblastoma (especially if q14 involved)

(6) gastrointestinal malformations, including Hirschsprung's disease


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