Red cell membrane alteration involving protein 4.1 and protein 3 in a case of recessively inherited haemolytic anaemia.

We present 2 siblings with a severe congenital haemolytic anaemia. Red cells displayed a variety of abnormal shapes, including leptocytes, schizocytes and elliptocytes. Repeatedly, skeletal protein 4.1 appeared reduced by 30%. The 4.1a/4.1b ratio was normal despite the haemolytic state. No change could be detected in spectrin, nor in sialoglycoproteins. Band 3 was denser, narrower and displaced downward. The parents, who are consanguineous, were devoid of any obvious biochemical abnormality; however, their red cells were not normal. These 2 cases with reduced protein 4.1 clearly depart from 4.1 (-) hereditary elliptocytosis. The possibility of an altered binding of protein 4.1 to some other membrane component is discussed.