Hb Lepore (Pylos)/Hb S compounds heterozygosity in two Greek families

American Journal of Hematology 49:131-134 (1995)

Hb Lepore (Pylos)/Hb S Compounds Heterozygosity in Two Greek Families E. Voskaridou, K. Konstantopoulos, P. Kollia, M. Papadakis, and D. Loukopoulos Thalassaemia Unit, Laikon Hospital, Athens (E.V., M.P.) and First Department of Medicine, University of Athens, Athens, Greece (K.K., P.K., D.L.)

We have studied three compound heterozygotes for Hb Lepore (“Pylos”)/HbS hemoglobin, a combination quite uncommon in the literature. It is of interest that while two of these cases are clinically similar to those thus far reported, the third one is free of symptoms and the diagnosis was put incidentally. This mild condition may be due to the high level of fetal hemoglobin produced. o 1995 Wiiey-Liss, inc. Key words: Hb Lepore, Hb S, Hb F

Family A

INTRODUCTION

Unlike classic thalassaemias, in Hb Lepore syndromes a structurally abnormal hemoglobin is produced. This abnormal hemoglobin has the same electrophoretic mobility as Hb S. Genetically, it arises from an unequal crossover event involving homologous portions of 6 and p globin genes. Three Lepore hemoglobins have been identified thus far, each differing in the site of 6-p crossover, namely, Lepore-Boston (also known as LeporeWashington or Hb Pylos), Lepore-Hollandia, and Lepore-Baltimore [ 1-41. The quantitative expression of the fusion gene is roughly intermediate between that of P and 6 genes, resulting in a P-thalassaemia-likecondition. Accordingly, heterozygous Hb Lepore resembles thalassaemia minor and the homozygous state results in a thalassaemia major-like condition respectively. Compound heterozygotes for Hb S/Hb Lepore are characterized by a sickling disease of moderate severity, spienomegaly, and haemolysis; vasoocclusive symptoms according to recent data range from mild to severe [5]. On the other hand, the condition may be readily confused with sickle cell anaemia because of the electrophoretic mobility of Hb Lepore which is identical to that of Hb S at alkaline pH. This may also partially explain the rarity of the documented Hb Lepore/Hb S cases in the literature [14, 61. We report the clinical and haematological features of two more families with this condition and compare the data with those of the already reported cases. 0 1995 Wiley-Liss, Inc.

Family 8

p thal trait

HbS heterozygote

Hb “Pylos”heterozygote ( )

Age

0

not examined dead

Fig. 1. Pedigrees of the two families (A and B) studied.

MATERIALS AND METHODS

Two unrelated Greek families were studied. The family pedigrees are depicted in Figure 1. Peripheral blood parameters were determined by standard methods on an automatic analyser. Hemoglobin was studied by electroReceived for publication July 18, 1994; accepted December 14, 1994. Address reprint requests to Dr. Ersi Voskaridou, Thalassaemia Unit, Laikon Hospital, GR-I 1527-Athens, Greece.

Voskaridou et al.

132

TABLE 1. Haematological Data of the Studied Members of the Families A and B ~~

~

Member

Hb (g/dl)

Ht

Retics.

HbF

Hb Pylos

HbA,

(%)

(%I

(%)

("/.I

(%I __

55 45 19 21

17.1 13.5 13.4 13.8

50.0 40.6 42.2 42.8

6.13 5.33 6.16 6.56

27.8 25.0 21.8 21.1

81.6 76.2 68.5 65.3

34.1 32.8 31.8 32.3

2 2 6 15