摘要:

Complete monosomy 21 is claimed to be a rare chromosomal disorder in which the cytogenetic investigation is bedevilled by technical difficulties. We describe the disparate clinical features in two patients in whom an initial diagnosis of monosomy 21 was made by routine karyotyping. Fluorescencein situhybridisation (FISH) confirmed a translocation of chromosome 21 material to the short arm of chromosome 5 and to the X chromosome, respectively. The usefulness of FISH in the investigation of subtle chromosomal rearrangements is hereby demonstrated. These findings also cast doubt on the existence of “pure” monosomy 21 as an entity, and suggest that partial monosomy 21 is a more likely occurre

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03219.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A 4‐year‐old Saudi female child with extreme failure to thrive, striking dysmorphic features, developmental delay, congenital hypoparathyroidism, UTI. seizures, chronic otitis media, chronic non‐specific gastroenteritis and repeated life‐threatening infections was followed from birth. She was the product of first‐cousin consanguineous marriage. She had striking facies with frontal prominence, deep‐set eyes, depressed nasal bridge, beaked nose, long philtrum with thin upper lip, micrognathia, large floppy ears, bifid uvula, and growth retardation with SD score<— 2 for height, weight and head circumference. We believe these features which include congenital hypoparathyroidism, severe growth failure and developmental delay in the absence of chromosomal abnormality represent a newly described genetically determ

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03220.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The patterns of X chromosome inactivation were determined in 14 females from three unrelated X‐linked severe combined immunodeficiency (XSCID) pedigrees. All the females were found to be heterozygous for the hypervariable DXS255 locus, enabling analysis of differential methylation of this locus in peripheral blood haematopoietic cells. All six obligate carriers manifested a unilateral X chromosome inactivation in the T lymphocyte population. Differential methylation analysis of T lymphocytes was subsequently applied to establish the carrier status of females at risk in the XSCID pedigrees. In the B lymphocyte population of four XSCID carriers a unilateral X chromosome inactivation was observed. Four other carriers had minor fractions and one carrier had a substantial fraction of B lymphocytes with the XSCID gene defect on the active X chromosome. Within single XSCID pedigrees the carriers manifested different patterns. In two pedigrees the granulocyte populations of all carriers showed a random distribution of X chromosome inactivation. In the third pedigree the granulocytes of the three carriers analyzed manifested complete inactivation of the X chromosome that carried the XSCID mutation, exposing a selective disadvantage of granulocytes that express the XSCID defect. The pedigree‐dependent differences in the involvement of the granulocyte population suggest the existence of two distinct XSCID defe

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03221.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Two hundred and twenty‐nine symptomatic patients with retinitis pigmentosa were ascertained in Slovenia between 1986 and 1990. Twenty‐three further patients were identified while data from 63 families (82 patients) were being collected. After correction for underascertainment, a prevalence of 1 in 6023 was estimated in the Slovene population (1999 477 in 1990). The highest prevalence of 1 in 1902 was found in the age group 65 years and older. Of 63 analysed families, 17 (27%) showed autosomal dominant, 13 (21%) autosomal recessive, and one family (1.5%) X‐linked inheritance; in 30 families (47.5%) isolated cases were found; and in two families the mode of inheritance was impossible to dete

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03222.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

We present a case previously described by Jenkins et al. (1983) as atypical Down syndrome (DS). The initial diagnosis was first made on the basis of phenotypic and cytogenetic data. This analysis was supported by studies of superoxide dismutase (SOD1) activity that maps to band 21q22.1. Results from phenotypic, chromosome banding and SODI studies suggested a karyotype of 46,XX,—12, + t(12pter to 12qter::21q21 to 21q22.?2). Using fluorescentin situhybridization (FISH) for chromosome painting with DNA libraries derived from sorted human chromosomes to stain selectively the chromosomes No. 21 and No. 12, we demonstrate that the marker chromosome 12q+ has no chromosome 21 content but it is derived from chromosome 1

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03223.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A 33‐year‐old woman and her 71‐year‐old mother were both found to have pseudohypoparathyroidism type I with Albright's hereditary osteodystrophy associated with a cytogenetic deletion of the proximal part of one chromosome 15, resembling that found in Prader‐Willi syndrome. As there are overlapping clinical features between these two syndromes a causal relationship cannot be excluded. However, molecular analyses with 10 probes from this region did not detect any uniparental disomy or deletion, features frequently found in Prader‐Wil

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03224.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Two of three unrelated children withde novocongenital complex chromosome rearrangements (CCR) with more than four chromosome breaks had cleft lip and palate as one of several congenital anomalies. In patient 1, unilateral complete cleft of the primary and secondary palates accompanied severe ectrodactyly, bilateral posterior choanal atresia and several minor congenital anomalies. Karyotypes of peripheral lymphocytes and skin fibroblasts showed five derivative chromosomes with six break points. There were two translocations, t(2;5), t(3;11) and an interstitial deletion, del(13)(q12q14). Patient 2 had a bilateral complete cleft of the lip and palate, in addition to slow pre‐ and postnatal growth and minor congenital anomalies. Peripheral lymphocytes and palatal mucosa fibroblasts karyotypes showed five derivative chromosomes with six break points. A partial deletion of 10p, two translocations, t(2;3), t(7;18) and an inversion of the derivative chromosome 2 were present. In both patients, a “major catastrophe” of unknown etiology in one of the parental gametes appeared to be the event leading to the stable CCR without evidence of persistent chromsome instability. All four parents had normal karyotypes. The presence of palatal clefts in these patients indicates that dysmorphologists and pediatricians have to consider CCR whenever taking care of a patient with cleft palate, particularly if additional anomalies, no matter how subtle, are present. The detection and interpretation of the latter anomalies are essential for the diagnosis and management of these patients. Accurate cytogenetic diagnosis determines the short‐ and long‐term prognosis and facilitates genetic counseling in regard to life‐span, quality of life and reproductive plans of patients

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03225.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

LHON has been suggested to involve both mitochondrial and X‐chromosome‐linked loci. By extending two‐locus mitochondrial and nuclear gene analytic methods, we recently proposed that a proportion of affected females are likely heterozygous at the X‐linked locus and affected due to unfortunate X‐chromosome inactivation. Assuming that the optic tissue is the primary site of action of the mutant gene(s), we further propose here that there should be no fewer than six embryonic precursor cells for the involved optic tissue at the stage in early development when X‐chromosome inactivation occurs. We also estimate that the disease threshold (i.e. proportion of cells with abnormal X‐chromosome active in the responsible tissue at the time of X‐chromosome inactivation) for a heterozygous female is in the range

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03226.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

One hundred and fifty‐eight women of advanced maternal age with complete follow up who experienced spontaneous fetal loss after prenatal diagnosis were studied for reproductive behaviour as well as prenatal diagnosis in a subsequent pregnancy. A higher rate of subsequent pregnancies amongst women who experienced an early spontaneous abortion after chorionic villus sampling (CVS) was expected compared with women who lost a pregnancy later during pregnancy after amniocentesis. Of the 92 women who underwent CVS in a previous pregnancy, 57 (62%) became pregnant again. Of the 66 women who underwent amniocentesis in the pregnancy that ended in fetal loss, 34 women (52%) had a subsequent pregnancy. The cumulative incidence of subsequent pregnancies was significantly influenced by maternal age but not by parity or the method of prenatal testing. Most women who decided on a new pregnancy opted for prenatal diagnosis. There was a preference for amniocentesis if the patient had previously undergone CVS. However, the reverse was not the cas

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03227.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

We describe two siblings, a male and a female pair, born of consanguineous parents, affected with a rare genetic form of congenital microcephaly. The clinical syndrome is characterized by early onset myoclonic seizures, spasticity, and profound psychomotor retardation without detectable brain malformations. To date, only two kindreds and one sporadic case with a similar clinical picture have been observed and reported (Tolmie et al. 1987, Bundey&Griffiths 1977). The severity of the neurological features and their perinatal onset differentiate the syndrome from the more common autosomal recessive microcephaly with spasticity/seizures.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1992.tb03228.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY