[Currarino syndrome: variability of imaging findings in 22 molecular-genetically identified (HLXB9 mutation) patients from five families].

PURPOSE: The imaging documents, obtained in connection with a primarily molecular genetic study on Currarino syndrome, should be evaluated with special respect to the constancy resp. the variability of findings in patients with proven HLBX9 mutations.
METHODS: In five female non-related index patients with clinico-radiologically diagnosed Currarino syndrome and further 53 members of their families, changes of the homeobox gene HLXB9 had been analysed. Variable mutations of this gene were found in a total of 23 individuals including the five index patients. In 22 of them the preexisting radiological documents could be collected as well as further imaging (plain sacrococcygeal radiography and/or lumbosacral MRI at least) initiated. This was followed by a detailed evaluation of pathological findings in the os sacrum/coccyx as well as in the presacral, the intraspinal, the anorectal, and the urogenital region, finally.
RESULTS: Imaging investigations revealed concomitant phenotypic abnormalities in all and even nine clinically asymptomatic individuals with proven HLXB9 mutations. A sacrococcygeal defect of varying intensity was depicted in every case. Complete Currarino triad (i. e. sacrococcygeal defect, presacral mass = anterior meningocele and/or tumor, anorectal malformation) was only found in the five index patients and three further relatives. In all other cases, one or more of the following anomalies were detected with variable combination and with decreasing frequency: anterior meningocele (12), presacral tumor (11), tethered cord (10), intraspinal lipoma (8), anorectal stenosis/atresia (8), syringocele (5), rectal fistula (3), urogenital (2).
CONCLUSION: Currarino syndrome should be considered as a differential diagnosis in all patients with chronic constipation since early infancy and its imaging index finding, i. e. a sacrococcygeal defect, should be looked for with plain radiography, first. In positive cases or other phenotypic suspicious constellations molecular genetic analysis for HLBX9 mutations should be the next step. If positive again, this should be followed by complete adequate imaging in the patient as well as by plain sacrococcygeal radiography in, at least, symptomatic family members.