X-linked dyskeratosis congenita with pancytopenia

Abstract

Two maternal male cousins in a Jewish Iraqi kindred were affected with dyskeratosis congenita and had a megaloblastic bone marrow. One cousin had pancytopenia and the other had thrombocytopenia. The kindred displays a deficiency of glucose-6-phosphate dehydrogenase (G6PD) and a beta-thalassemia trait. The following genetic "markers" of the X chromosome were studied: G6PD, the X-linked blood groups Xg, and color vision. Linkage analysis indicated that dyskeratosis, G6PD, and Xg are far apart on the X chromosome. Chromosomal studies showed a 46XY karyotype in both cases; however, nonspecific numerical aberrations and structural abnormalities were found in the first and in the second case, polyploidy was seen in four of 60 cells. The proband's cultured fibroblasts did not show increased susceptibility to malignant transformation by simian virus 40, an oncogenic virus.

Dyskeratosis congenita. Report of a large kindred

“…This seems to be the usual method of inheritance (McKusick, 1978), although one family with autosomal dominant inheritance has been reported (Scoggins et ai, i^ji). Our study confirms the findings of Gutman et al (1978) that the dyskeratosis congenita and Xg^ blood group loci are widely separated on the X chromosome. Thus linkage is not an aid in genetic counselling in this disorder and this is unfortunate as the carrier females are not at present detectable by other means.…”

Dyskeratosis Congenita Associated with Elevated Fetal Hemoglobin, X‐Linked Ocular Albinism, and Juvenile‐Onset Diabetes Mellitus

“…Levels of HbF were elevated in 15 reported cases of dyskeratosis congenita (9-21). Of this group, all of the cases that were pedigrees in which patterns of inheritance could be determined demonstrated X-linked inheritance (10,12,13,16,17). The average HbF for 12 of these patients was 9.5% and the range was 3.0% to 29.6%.…”

Congenital alopecia and nail dystrophy associated with severe functional T-cell immunodeficiency in two sibs

“…Diagnostic criteria include the classical triad, consisting of a reticular pattern of hyper-and hypopigmentation of the skin, nail dystrophy, and mucosal leucoplakia [Davidson and Connor, 19881. This genetic disorder is often associated with bone marrow failure [Gutman et al, 1978;Friedland et al, 19851. Mild T-cell abnormalities, in association with an apparently normal lymphocyte-activation process, have also been described in patients with this syndrome [Lee et al, 19921. However, in our patients two of the major diagnostic criteria of DC, i.e., abnormal pigmentation of the skin and mucosal leucoplakia, were lacking, and furthermore, the immunological abnormalities were different from those reported in patients with DC in both severity of clinical course and type of alterations [Ortega et al, 1972;Lee et al, 19921. Increasing evidence indicates that the SCID phenotype is a heterogeneous condition [Matsumoto et al, 19921, in which a block at different stages of cell differ-…”