A novel splicing mutation in the albumin gene (c.270+1G>T) causes analbuminaemia in a German infant

Congenital analbuminaemia is a rare autosomal recessive disorder manifested by the presence of a very low amount of circulating serum albumin. The clinical diagnosis may be challenging because of the absence of unambiguous symptoms and because hypoalbuminemia may have many causes different from a genetic lack of the protein. We describe the clinical and molecular characterization of a new case of congenital analbuminaemia in an infant of apparently non-consanguineous parents from Treves, Germany. For molecular diagnosis, we used our strategy, based on the screening of the albumin gene by single-strand conformation polymorphism, heteroduplex analysis and direct DNA sequencing, which revealed that the proband is homozygous and both parents are heterozygous, for a novel G>T transversion at nucleotide c.270+ 1, the first base of intron 3. The mutation inactivates the strongly conserved GT dinucleotide at the 5 splice site consensus sequence of this intron. In conclusion, we report the clinical findings and the molecular defect of this case, which contributes to a better understanding of the biological mechanism of congenital analbuminaemia.