A rare microduplication in a familial case of annular pancreas and duodenal stenosis.

Background/purpose: We describe a 3-day-old male infant that was operated on for annular pancreas causing duodenal stenosis. The family history revealed that the mother also underwent surgery as a neonate owing to duodenal stenosis with an annular pancreas. The aim of our study was to perform molecular investigations in this rare and familial congenital malformation.

Methods: We performed high-resolution (180 K) array comparative genomic hybridization using the infant's DNA and multiplex ligation-dependent probe amplification (MLPA) using the parents' and the affected mother's siblings' and parents' DNA.

Results: Array comparative genomic hybridization revealed previously unreported duplications on chromosome 6q24.2 and 17q22-q23.1, respectively, in the infant's DNA, and the latter duplication was also found in the healthy father using MLPA, whereas the affected mother carried the 6q24 duplication (0.7 Mb) containing parts of the utrophin gene. We further performed MLPA analysis of the 6q24 region and found that the clinically unaffected grandfather was a carrier of the microduplication, and so were 2 asymptomatic siblings of the affected mother.

Conclusions: The 6q24.2 mircoduplication of the utrophin gene is a potential risk factor for the development of annular pancreas, but further studies will clarify the exact role and if this is a true risk factor or a rare normal variant.