del(5)(p) – cri du chat

Epidemiology and Etiology:

· Terminal or interstitial deletion of 5p

· De novo (sporadic) mostly (80%)

· Paternal homologue (80%)

· Derivative inherited from parents with translocation (10-15%)

· Other unusual cytogenetic aberration

Common sites:

·

Gross features:

· Distinctive facies

· Microcephaly

· Hypertelorism

· Epicanthal folds

· Low-set ears

· Preauricular tags

· Micrognathia

· Heart defects

· Impaired growth

Histologic features:

·

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

· Very variable breakpoints

· 5p13.3 (~10 Mb deletion)

· 5p10 (~45 Mb deletion)

· Severity of clinical manifestations and psychomotor retardation is correlated to size of the deletion

· 5p15 is critical region

· Regions associated with phenotypes have been mapped out:

· From proximal to distal:

· Mental retardation (5p15.2)

· Facial phenotype (5p15.2)

· Cat cry (5p13)

· speech

Other features:

· Mewing cat cry

· Mental retardation (moderate to severe)

References:

· Nussbaum RL, McInnes RR, Willard HF. Thompson & Thompson Genetics in Medicine: With STUDENT CONSULT Online Access. 7th ed. Saunders; 2007.

· DECIPHER v4.4 (accessed 2010)