Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 1990 the existence of an X linked form of the alpha thalassaemia/mental retardation syndrome was postulated after the description of six isolated cases who were all cytogenetically male. The segregation pattern in the family described here supports X linked inheritance. The clinical details of our two patients are remarkably similar to the previously delineated phenotype. In addition, renal anomalies were identified in one patient, but their significance will remain uncertain until further cases have been assessed. Affected subjects could be identified by the presence of Hb H inclusions, and were also noted to have abnormalities of several haematological indices. Examination of blood from obligatory carriers in this family suggests that Hb H inclusions are not an invariable finding and that haematological indices appear to be unaffected by the condition in female heterozygotes.
 ...
PMID:Alpha thalassaemia/mental retardation syndrome (non-deletional type): report of a family supporting X linked inheritance. 177 May 28

We describe three males (two brothers and a cousin) who have the X linked alpha thalassaemia/mental retardation (ATR-X) syndrome. The diagnosis, originally suspected in the brothers because of similarity in dysmorphic features to previous cases, was confirmed haematologically in the surviving brother. The cousin has less typical dysmorphism and a virtually normal routine blood count, but haemoglobin H inclusions were found in his red blood cells showing that he has the same condition. This report expands the clinical phenotype of the ATR-X syndrome and emphasises that a normal blood count does not exclude the diagnosis.
 ...
PMID:X linked alpha thalassaemia/mental retardation: spectrum of clinical features in three related males. 177 May 29

It has previously been suggested that the non-deletion form of the alpha thalassaemia/mental retardation syndrome may be an X linked disorder. We describe four brothers with this syndrome in whom the diagnosis was first suspected because of their characteristic clinical features, although these varied somewhat from one sib to another. The diagnosis was confirmed in each case by showing Hb H inclusions in a proportion of their red blood cells. The identification of four similarly affected boys in this pedigree is consistent with an X linked pattern of inheritance. In support of this, very rare Hb H inclusions could be found in the red blood cells of the mother and one sister who both share some facial features with the affected boys and are presumably carriers of this disorder. This pedigree thus provides further evidence that this is an X linked syndrome and indicates the clinical and haematological variability that may exist even within a single affected family.
 ...
PMID:The non-deletion alpha thalassaemia/mental retardation syndrome: further support for X linkage. 177 May 30

The rare association of alpha thalassaemia and mental retardation has been described previously. Molecular studies of the alpha globin cluster in these cases have been heterogeneous, with some patients having large deletions while in others the alpha globin complex appears to be intact (non-deletional). The non-deletional cases form a distinct group whose features include severe mental retardation, haematological changes of haemoglobin H (Hb H) disease, developmental defects, and unusual patterns of inheritance. To date, five cases have been described with non-deletional alpha thalassaemia-mental retardation. We present here a further example of a young male of Northern European origin who appears to have the non-deletional form of the disease. Clinical features included severe mental retardation, Hb H disease, and developmental defects similar to those reported previously. DNA mapping, including pulsed field electrophoresis, showed no evidence of deletions within the alpha globin cluster. Karyotypic analysis indicated an increase in random breakage, which has been observed previously in one case of deletional alpha thalassaemia-mental retardation. Profuse Hb H bodies and Hb H on electrophoresis were consistent with Hb H disease. However, the latter was present at a relatively low level (1.6%) and, as well, the mean corpuscular volume (82.8 fl) and mean corpuscular haemoglobin (26.4 pg) were surprisingly high. Our findings are compared to other cases described with the non-deletional Hb H-mental retardation syndrome.
 ...
PMID:Occurrence of the alpha thalassaemia-mental retardation syndrome (non-deletional type) in an Australian male. 223 51

The genetic and acquired disorders of human haemoglobin provide a diverse group of naturally occurring models for analysing the regulation of protein synthesis. They include structural haemoglobin variants, thalassaemias, which are conditions in which there is a reduced rate of globin chain production, and hereditary persistence of foetal haemoglobin (HPFH) in which there is an inherited abnormality in the switch from foetal to adult haemoglobin synthesis. The thalassaemias result from a diverse series of cis acting lesions of the globin genes which include deletions, insertions, frame shift mutations, and point mutations involving transcription, messenger RNA processing, initiation, termination, poly A addition and globin chain stability. Many forms of HPFH are due to deletions of the beta-like gene cluster; it has been suggested that they may involve regions of the cluster which are involved in the regulation of the foetal to adult globin chain switch. So far, however, no regions of this type have been identified with certainty. The varieties of HPFH not associated with major gene deletions, or those caused by genetic determinants that are not linked to the globin gene clusters, and some of the acquired forms of alpha thalassaemia associated with mental retardation or leukaemia, may be more useful models for studying the regulation of the globin genes, particularly their developmental control.
 ...
PMID:Genetic disorders of human haemoglobin as models for analysing gene regulation. 608 52

Each of three families of northern European origin contains a mentally retarded son with hemoglobin H (Hb H) disease. One parent is a carrier of mild alpha-thalassemia and the other is normal, suggesting that this form of Hb H disease results from the interaction between an inherited defect of alpha-chain production and one member of the pair in chromosome 16 and a new mutation on the other. Restriction-enzyme analysis indicated that the new mutation was not the same in the other three patients, and demonstrated at least two hitherto undescribed lesions involving the alpha-globin gene cluster. Unless the association between the Hb H disease and mental retardation is fortuitous, the new mutations may also be related to the development changes in these children. Since the mutations only came to light because there was concurrent inheritance of an additional alpha-thalassemia determinant, this type of mutation of chromosome 16 may have been overlooked in other mentally retarded patients.
 ...
PMID:Hemoglobin H disease and mental retardation: a new syndrome or a remarkable coincidence? 626 62

The child with haemoglobin H (HbH) disease and multiple congenital abnormalities reported by Borochowitz et al (1970) has been more fully investigated in view of the recent report by Weatherall et al (1981) of a 'new' syndrome of HbH disease and mental retardation. Restriction enzyme analysis indicates that the child's HbH disease results from the inheritance of an alpha-thalassaemia 2 chromosome (-alpha/) from his mother and, from his father, a chromosome which has undergone a deletion including the zeta- and alpha-globin genes as well as an undefined length of DNA. Striking similarities between our patient and Weatherall et al's patients at the clinical level and between our patient and their patient number 1 at the molecular level, confirm that a new syndrome has been defined.
 ...
PMID:The haemoglobin H disease mental retardation syndrome: molecular studies on the South African case. 670 28

The ATR-X syndrome is an X-linked disorder comprising severe psychomotor retardation, characteristic facial features, genital abnormalities, and alpha-thalassemia. We have shown that ATR-X results from diverse mutations of XH2, a member of a subgroup of the helicase superfamily that includes proteins involved in a wide range of cellular functions, including DNA recombination and repair (RAD16, RAD54, and ERCC6) and regulation of transcription (SW12/SNF2, MOT1, and brahma). The complex ATR-X phenotype suggests that XH2, when mutated, down-regulates expression of several genes, including the alpha-globin genes, indicating that it could be a global transcriptional regulator. In addition to its role in the ATR-X syndrome, XH2 may be a good candidate for other forms of X-linked mental retardation mapping to Xq13.
 ...
PMID:Mutations in a putative global transcriptional regulator cause X-linked mental retardation with alpha-thalassemia (ATR-X syndrome). 769 14

Genital abnormalities have been noted in several patients with the X-linked form of alpha-thalassemia and mental retardation syndrome (ATR-X). The initial clinical report of the condition documented a phenotypic female with 46,XY karyotype. To this we now add 2 further siblings with abnormalities of the external genitalia, manifesting as male pseudohermaphroditism.
 ...
PMID:Male pseudohermaphroditism in sibs with the alpha-thalassemia/mental retardation (ATR-X) syndrome. 772 24

The hallmarks of the X-linked alpha-thalassemia/mental retardation (ATR-X) syndrome are severe psychomotor retardation, minor facial anomalies, genital abnormalities, and an unusual form of alpha-thalassemia. The demonstration of HbH inclusions in red blood cells after incubation with brilliant cresyl blue confirms the diagnosis. We describe 15 previously unreported cases and analyse the phenotypic and hematologic findings in these subjects and compare them with previously published cases. This study demonstrates the consistency of the main characteristics of this syndrome and extends the phenotype. Developmental changes in phenotype, in particular the coarsening of the facial appearance, are illustrated. The hematologic findings are shown to vary widely; in some cases the manifestation of alpha-thalassemia may be subtle and missed without repeated examination.
 ...
PMID:Clinical and hematologic aspects of the X-linked alpha-thalassemia/mental retardation syndrome (ATR-X). 772 25


1 2 3 4 5 6 7 8 9 10 Next >>