SSBP Information Sheet
Deletion 9p Syndrome

Alternative names: 9p Monosomy, 9p- syndrome

First described:
Alfi et al (1973). Since then a least 40 similarly affected patients with 9p- as the sole chromosomal anomaly have been reported.

Etiology:
deletion of genetic material from chromosome 9p. In most cases the breakpoint is in band p22. The deletion is de novo in 2/3 of cases.

Physical phenotypes:
trigonocephaly, flat occiput, up-slanting palpebral fissures, arched eyebrows, bilateral epicanthal folds, prominent eyes secondary to hypoplastic supraorbital ridges, flattened nasal bridge, short nose with anteverted nares, long philtrum, small mouth, highly arched palate, micrognathia, low-set poorly formed ears, short neck with low hairline, increased internipple distance, lnong middle phalanges and short distal phalanges of the fingers with short nails, simian crease. In 1/3 to ½ of th epatiens ther may be ventricular septal dfects, patient ductus arteriosus and/or pulmonic stenosis. Males are likely to have micropenis and/or cryptorchidism, and femailes hypoplastic labia majora.

Age of detectability:
at birth. Prenatal diagnosis is possible by chromosome studies of chorionic villi or anmotic fluid cells.

Prognosis:
depends on the severity of associated malformations. In the absence of major congenital heart malformations, life span is normal. A 61 year old man with del (9p22) has been described.

Behavioural and cognitive characteristics:
mental etardation appears to be mild to moderate, with IQ ranging between 30 and 73. Social adaptation is often good. The typical pesonality is described as friendly, affectionate, and socialable. For a more detailed despreptionof the behavioural phenotype, please see the paper on "The del (9p) syndrome by A Battaglia et al.

A Battaglia. August 2000

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