Congenital Analbuminemia Attributable to Compound Heterozygosity for Novel Mutations in the Albumin Gene (Technical Briefs‪)‬

Congenital analbuminemia is a rare autosomal recessive disorder characterized by the absence or very low concentrations of serum albumin (HSA) (1). The disorder is conventionally defined as an HSA 1 g/L (as determined by immunoassay) associated with normal liver function and absence of protein loss (2). The incidence of congenital analbuminemia is estimated to be 1 in 1 million births, without sex or race predilection. To date, 39 cases of congenital analbuminemia have been reported, 16 of which were diagnosed in children (3). Despite multiple functions of HSA (4), its absence is a relatively tolerable condition. Except for associated hyperlipidemia, minor edema, and mild fatigability, analbuminemic individuals suffer few adverse symptoms (3, 5, 6). Such relative mildness of symptoms is attributed to a compensatory increase in hepatic biosynthesis of other plasma proteins (7, 8). Congenital analbuminemia is attributable to defects in the gene coding for HSA. The HSA gene is located on chromosome 4 and is split into 15 exons by 14 intervening introns (9). The identification of multiple mutations that cause analbuminemia clearly indicates that it is a genetically heterogeneous disorder. Six of these mutations introduced stop codons (10-13), and 2 caused splicing defects and determined a premature termination of the translation (14, 15). All were found to be present in the homozygous state. In the present study we characterized another case of congenital analbuminemia caused by 2 newly identified mutations in an Italian family.