Co-inheritance of the rare ß hemoglobin variants Hb Yaounde, Hb Görwihl and Hb City of Hope with other alterations in globin genes: impact in genetic counseling.

ABSTRACT

PURPOSE: Nearly 1183 different molecular defects of the globin genes leading to hemoglobin variants have been identified (http//globin.bx.psu.edu) over the past decades. The purpose of this study was to report three cases, never described in the literature, of co-inheritance of three ß hemoglobin variants with other alterations in globin genes and to evaluate the clinical significance to conduct an appropriate genetic counseling. PATIENTS AND METHODS: We report the molecular study performed in three probands and their families, sampling during the screening program conducted at the Laboratory for Molecular Prenatal Diagnosis of Hemoglobinopathies at Villa Sofia-Cervello Hospital in Palermo, Italy. RESULTS: This work allowed us to describe the co-inheritance of three rare ß hemoglobin variants with other alterations in globin genes the ß hemoglobin variant Hb Yaounde [ß134(H12)Val>Ala], found for the first time in combination with ααα(anti3.7) arrangement, and the ß hemoglobin variants Hb Görwihl [ß5(A2)Pro>Ala] and Hb City of Hope [ß69(E13)Gly>Ser], found both in association with ß(0) -thalassemia. CONCLUSION: The present work emphasizes the importance of a careful evaluation of the hematological data, especially in cases of atypical hematological parameters, to carry out an adequate and complete molecular study and to formulate an appropriate genetic counseling for couples at risk.