Currarino syndrome (or triad) is defined as a partial sacral agenesis associated with a presacral mass and ano-rectal malformation. The partial sacral anomaly is an anterior defect. The first sacral vertebra is not affected, and the hemi-sacrum below usually takes the form of a sickle or crescent with the so-called scimitar sign at X-rays. The presacral mass is well visualized by MRI, it can be an anterior meningocele, an enteric cyst or a presacral teratoma. Surgical resection of the presacral mass, whatever its type, is recommended, because it may relieve patients from some symptoms linked to local pressure (eg constipation, urinary incontinence, dysmenorrhoea and dyspareunia). The clinical features of spinal cord tethering require surgical intervention releasing the tethering and prevent the progressive nature of the problem at the maximum level of traction (sphincter dysfunction, constipation). The ano-rectal malformation is either a stenosis or an atresia and surgical intervention in the neonatal period is required in those with severe forms. Familial forms have been already noted in early case reports and the underlying gene defect was localised to chromosome 7q36. Mutations in a homeobox gene, HLXB9, were identified in several affected patients: nearly all those with a familial form of Currarino syndrome, and 30% of those with sporadic forms. Mutations have not been identified in the remainder of sporadic cases suggests an unidentified mutation in another part of the gene, genetic heterogeneity or somatic mosaicism. Currarino syndrome is an autosomal dominant disorder with reduced penetrance and low level of de novo mutations. Expressivity is variable, which makes it difficult to evaluate the true prevalence of the syndrome: 39% of patients present with a severe phenotype, 29% are clinically apparent, 28% have X-ray changes only, and 4% are asymptomatic. Females are more frequently affected, they often have associated gynecological and urinary tract problems. Age at presentation varies greatly, ranging from birth to 64 years. All first-degree relatives should be offered a pelvic X-ray. Those with an abnormal x-ray should be referred to a surgeon for further investigation. In a few cases, deletions of 7q were reported. Prenatal diagnosis is rarely made, and relies on the detection of a sacrococcygeal mass. Mutational or linkage analysis on fetal cells is possible providing the mutation is known or the family structure is suitable.
Last update: April 2003
- Dr Elisabeth ROBERT-GNANSIA