`Met de verkeerde in zee gaan' : diagnostiek naar thalassemie

We present a 7-year-old boy with microcytic, hypochromic anaemia, without depletion of iron reserves. As both parents were known carriers of ß-thalassemia, prenatally both ß-thalassemia major and minor had been excluded. Extensive diagnostics showed a rare form of a-thalassemia, seen relatively frequently in Sardinia, caused by a point mutation in the initiation codon of the a2-locus. As athalassemia is generally caused by deletions in the a-globin genes and point mutations will only be detected by sequence analysis, this type of mutation will be missed when only a-globin gene deletion screening is performed.