Abstract
The proband is an elderly woman (79 years of age) of Surinamese–Hindustani origin, suspected of being a carrier of a nondeletional α‐thalassemia (thal) because of a moderate microcytic hypochromic anemia at normal ferritin levels and in the absence of any other α‐thal deletions. Sequence analysis revealed a silent mutation (GGC→GGT) at codon 22 of the α2‐globin gene. This mutation generates a splice donor site consensus sequence (GGTGAG) between codons 22 and 23. The abnormally spliced mRNA leads to a premature termination between codons 48 and 49. The presence of a downstream intron may induce the intracellular degradation of the affected mRNA, a pathway known as nonsense mediated decay (NMD), and this explains the α+‐thal phenotype observed in the patient. The codon 22 (GGC→GGT) transition described in this report is the first mutation creating a splice donor site in one of the α‐globin genes.