1/9. incontinentia pigmenti: XXY male with a family history.We report on the case of a male who from the start of life displayed vesicular lesions; on the trunk these were clustered and on the limbs they adopted a linear configuration. After biopsy of one such lesion, the histopathological study was compatible with a diagnosis of incontinentia pigmenti (IP). In the following months, hyperkeratotic lesions appeared which later became pigmented. The mother and other female members of the family also showed different degrees of alteration related to the same disease. The karyotype study showed the existence of 47,XXY (klinefelter syndrome). The exceptional nature of this case is that although it is the third case reported in the literature of a male affected by incontinentia pigmenti with a previous family history, it is the only one combining this characteristic with the presence of a 47,XXY karyotype.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/9. fragile x syndrome and neoplasia.Among 100 males with fragile X [fra(X)] or Martin-Bell syndrome, two have developed malignancies. The first case, a 57-year-old man with fra(X) expression in 12% of peripheral blood lymphocytes, developed a seminoma of the left testis at age 45 years and in the right testis at age 50 years. The second case, a 16-year-old white boy with fra(X) expression in 23% of lymphocytes, developed a mucin-producing adenocarcinoma of the colon at age 14 years. Because of the unusual nature of the tumors observed in these patients and in 2 other patients from the literature, we suggest that individuals with the fra(X) syndrome may be at increased risk of cancer.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/9. Endocrine and immunogenetic evaluation of an XX male infant with perineoscrotal hypospadias.To clarify the origin of the genital ambiguity occasionally associated with the XX male syndrome, a series of endocrinological studies were undertaken in an affected 6 months old infant with perineoscrotal hypospadias. The patient fulfilled all the diagnostic criteria of the syndrome: the testes were descended bilaterally, the Mullerian derivatives were absent, the 46,XX chromosome complement was ascertained in different cell lines, and male levels of h-y antigen were detected in cultured skin fibroblasts. Circulating gonadotrophin levels and pituitary LRH responsiveness were within normal limits for the age group. serum testosterone (T) levels were normal, and gonadal stimulation with hCG caused a significant rise on serum T. Incubations of [3H]T with fibroblasts from genital skin revealed normal activity of steroid 5 alpha-reductase. Moreover, normal concentrations of thermostable cytosol androgen receptors were revealed in cultured fibroblasts. Altogether the results indicated that ambiguity of the external genitalia in this patient was the result of neither abnormal T biosynthesis, peripheral A-ring T reduction, nor androgen intracellular specific binding, and suggested that the nature of the incomplete virilization could be a non-endocrine independent event associated to this disorder. The data are also consistent with the notion that testicular impairment observed in adult XX males develops later in life.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/9. Demonstration of the fra(X) in lymphocytes, fibroblasts, and bone marrow in a patient with a testicular tumour.A man aged 34, whose mental retardation and appearance were consistent with the fra(X)(q28) syndrome, had a craggy lump in his left testis. The fragile X was found in lymphocytes, fibroblasts, and bone marrow. The testicular tumour was benign and inflammatory in nature and within the testis spermatogenesis was absent.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/9. A marker x chromosome associated with nonspecific male mental retardation. The first South African cases.This report describes the first cases of X-linked mental retardation with a marker x chromosome seen in south africa, and forms part of an ongoing study. The marker was found in 11 affected males and 1 carrier female in 4 families investigated. The demonstration of the marker x chromosome characterized by a fragile site at the long arm (fra(X) (q27) in association with nonspecific X-linked mental retardation heralds a new era in cytogenetics. The attention of human geneticists everywhere is focused on various aspects of this fascinating phenomenon. It has now become possible to diagnose an apparently common familial cytogenetic condition with a high risk of recurrence and to identify female carriers; perhaps in time we will be able to provide prenatal diagnosis. Because of the familial involvement through X-linked inheritance the syndrome is believed to be more common than trisomy 21. The nature of the association of mental retardation with the marker x chromosome is unknown, but it could be related to close linkage with abnormal gene(s) or due to faulty transcription of the genes beyond the fragile site.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/9. Dicentric chromosome Y associated with Leydig cell agenesis and sex reversal.The nature of a non-mosaic marker y chromosome observed in a pseudohermaphrodite patient with Leydig cell agenesis was investigated by high-resolution chromosome analysis and molecular probes from the y chromosome. Cytogenetically, the marker chromosome appeared to be an isodicentric, with breakage in Yq11.21. Double copies of all Yp-specific loci tested, including SRY, were present. The most distal Yq portion detected in patient dna was DXS278-C, which maps to interval D in the chromosome Yq deletion map. Fragment DXS278-B, which maps to deletion interval E, was absent. The possible relationship between this cytogenetic abnormality and Leydig cell agenesis, a finding never reported in association with y chromosome rearrangements, is discussed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/9. Absent chondrodysplasia punctata in a male with an Xp terminal deletion involving the putative region for CDPX1 locus.This is a follow-up report on a male patient with a 46,Y,r(X) karyotype. Although he had no clinico-radiological features of X-linked recessive chondrodysplasia punctata (CDPX1), molecular studies revealed an Xp terminal deletion involving the putative region for the CDPX1 locus (PABX-DXS31). We suspect that the absence of CDPX1 may be attributable to the nature of the disease and the extreme short stature of the patient (mean -5.6 S.D.).- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/9. Premutation for the Martin-Bell syndrome analyzed in a large Sardinian family: III. Molecular analysis with the StB12.3 probe.This report complements a series of clinical, cytogenetical, and psychological studies previously reported on a large Sardinian pedigree segregating for premutations and full mutations associated with the Martin-Bell syndrome (MBS). Using the StB12.3 probe, we report now the molecular classification of all of the critical members of the pedigree. These molecular findings are evaluated against the variable phenotypic manifestations of the disease in the course of a six-generation segregation of an MBS premutation allegedly present in a common female progenitor of 14 MBS male patients and 9 female MBS heterozygotes seen in the last two generations. The nature and stepwise progression of MBS-premutations toward the fully manifested Martin-Bell syndrome and the possibility of reverse mutational events toward the normal allele are discussed with respect to the application of the presently available diagnostic tools in genetic counselling.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/9. Characterization of an isodicentric Y-chromosome for the long arm in a newborn with mixed gonadal dysgenesis.A newborn infant was referred for evaluation because of ambiguous genitalia. Examination of the genitalia revealed a hypospadiac phallus measuring 1.5 cm in length with chordee. Subtle phenotypic features consistent with turner syndrome were present including hypertelorism, anti-mongoloid slant to the eyes, mild widening of the neck, but no definitive webbing, shield like chest and positive cubitus valgus. A pelvic and renal sonogram confirmed the presence of a uterus and normal-appearing kidneys. There was incomplete fusion of the scrotum. No gonads were palpable within the scrotal sac. The patient was assigned a female gender on the basis of the presence of a uterus, the phenotypic appearance of the genitalia and the malignant potential of the gonads. The cytogenetic findings with QFQ-banding revealed an abnormal karyotype, i.e., mos 46,X,idic(Y) (p11.2)[77]/45,X[29]/46,X,idic(Y) (p11?) [2]/ 47,XY,idic(Y)(p11.2)[2]/47,X,idic(Y)(p11.2), idic(Y)(p11.2)[1]/46,XY[1]. The presence of an abnormal isodicentric Y-chromosome was evaluated by FISH-technique to ensure a finer characterization than routine methods. The genotype-phenotype correlation could not be established since mosaicisms of highly variable nature can exhibit an unpredictable outcome.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |