Cri-du-chat syndrome.

Background: Cri-du-chat syndrome is a genetic disorder associated with various sized deletions of the short arm of chromosome 5. There are typical physical features, but individual phenotypes vary considerably.

Methods: The records of 23 patients with cri-du-chat syndrome admitted to Mackay Memorial Hospital from June 1984 to February 2006 were retrospectively reviewed. Data abstracted from the records included abnormal facial features and physical findings, results of echocardiography, bronchoscopy, auditory evoked potential, visual evoked potential, brain ultrasonography, and karyotype. We examined the various clinical phenotypes to see if there was an association with specific karyotypes.

Results: Among congenital heart conditions, atrial septal defect (8/15, 53%) was the most common, followed by ventricular septal defect (4/15, 26%), tricuspid regurgitation (4/15, 26%) and patent ductus arteriosus (3/15, 20%). Laryngomalacia was the most frequent airway problem (8/23, 34%) and strabismus the commonest visual disorder (1/23). A high percentage of patients had impaired hearing (5/23, 21%). There was no clear relationship found between deletion size and major clinical manifestations in this study.

Conclusions: Karyotype is not a reliable indicator of specific organ involvement in cri-du-chat syndrome. However, karyotyping is still useful, particularly if parental translocation are found to be involved. It helps for prenatal diagnosis of next pregnancy.