Cases reported "Sex Chromosome Disorders"

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1/22. De novo dup(X)(q22.3q26) in a girl with evidence that functional disomy of X material is the cause of her abnormal phenotype.

    The relationship between phenotype and Xq duplications in females remains unclear. Some females are normal; some have short stature; and others have features such as microcephaly, developmental delay/mental retardation, body asymmetries, and gonadal dysgenesis. There are several hypotheses proposed in the literature to explain this variability. We describe a 7-year-old girl with dup(X)(q22.3q26). The pregnancy was complicated by intrauterine growth retardation, and she was distressed during labor. During her first year she fed poorly and failed to thrive. She has microcephaly, her height is at the 10th centile, and her hands and feet are strikingly small. She is hypotonic and delayed. Asymmetries of muscle power, and of leg and foot length have been noted. She has mild unilateral ptosis. She has some features of turner syndrome, and multiple other minor anomalies such as flat labia. These are features common to other described females. This report describes our patient in detail and compares her phenotype to those of the other females with Xq duplications, displays our laboratory investigations, and discusses ideas regarding the pathogenesis of phenotype. The duplicated X is of paternal origin. It is inactivated in all cells; however, the distal duplicated portion appears to be active. We suggest that functional disomy of the duplicated X material, due to local escape from inactivation, may be responsible for the phenotype in the affected females. ( info)

2/22. Prenatal sonographic diagnosis of the 49,XXXXY syndrome.

    The 49,XXXXY syndrome is a rare sex chromosome anomaly with an approximate incidence of 1 in 85,000 male live births. The diagnosis is usually ascertained postnatally by the association of mental retardation, variable growth deficiency, down syndrome-like facial dysmorphy, hypogenitalism and other malformations, especially involving the heart and skeleton. prenatal diagnosis of the pentasomy 49,XXXXY is generally fortuitous and sonographic features have rarely been described in the literature. We report here on two cases of 49,XXXXY syndrome diagnosed prenatally because of sonographic abnormalities. In the first, amniocentesis was performed at 26 weeks' gestation for polyhydramnios, unilateral clubfoot and micropenis. In the second, a karyotype was carried out on chorionic villi at 13 weeks' gestation for cystic hygroma. These observations and the six previously reported cases demonstrate that cystic hygroma in first or second trimester of pregnancy may be associated with sex chromosome aneuploidy other than turner syndrome. Moreover, they emphasize the importance of detailed sonographic examination in the second trimester, as small penis and abnormal posturing of the lower extremities are very suggestive of the 49,XXXXY syndrome. ( info)

3/22. Reproductive genetic counselling in non-mosaic 47,XXY patients: implications for preimplantation or prenatal diagnosis: Case report and review.

    With an incidence of approximately 1 in 500 male newborns, the 47,XXY genotype is one the most common sex chromosome anomalies. It is also the most frequent genetic cause of human infertility. Some non-mosaic 47,XXY patients have sperm production which allows infertility treatment to be offered by ICSI. Therefore, the risk of transmitting a chromosome anomaly to the next generation is an important problem in reproductive genetic counselling of these patients. Here, we report on a twin pregnancy where two karyotypically normal neonates 46,XX and 46,XY were born after the use of ICSI in assisted reproduction of a patient with a non-mosaic 47,XXY syndrome. To date, only 38 evolving pregnancies including the present cases, have been reported after ICSI using sperm from non-mosaic 47,XXY patients. Although these data are scarce, they suggest that the risk of chromosome anomaly in the offspring of these patients is low; hence, their reproductive genetic counselling can be reassuring, and management of the pregnancy can proceed with caution. ( info)

4/22. Neurologic aspects of 49,XXXXY syndrome.

    49,XXXXY syndrome is a rare sex chromosome aneuploidy syndrome characterized by mental retardation, severe speech impairment, craniofacial abnormalities, multiple skeletal defects, and genital abnormalities. We describe a 13-year-old boy with 49,XXXXY syndrome, language impairment, seizures, and left-hemisphere magnetic resonance imaging abnormalities and review the distinctive neurologic, cognitive, and behavioral phenotypes associated with this disorder. Finally, we discuss testosterone supplementation in the treatment of this syndrome. ( info)

5/22. Tall stature, insulin resistance, and disturbed behavior in a girl with the triple X syndrome harboring three SHOX genes: offspring of a father with mosaic klinefelter syndrome but with two maternal X chromosomes.

    AIMS: To describe the tall stature and its possible underlying mechanism in a Caucasian girl (age 12 years and 10 months) with 46,XX (28%)/47,XXX (72%) mosaicism and to identify the parental origin of her extra x chromosome. methods: The fasting glucose-to-insulin ratio was studied. The karyotypes of the girl and her parents as well as the presence of SHOX copies and the parental origin of her extra x chromosome were assessed. RESULTS: Clinical examination revealed a tall stature and severe acne, and endocrinological/metabolic assessment revealed insulin resistance. fluorescence in situ hybridization cytogenetic analysis depicted the presence of three SHOX genes in the 47,XXX cell line of the patient. karyotyping of her parents showed a normal 46,XX karyotype in the mother and 46,XY(93%)/47,XXY(7%) Klinefelter mosaicism in the father. However, dna analysis unequivocally showed maternal origin of the extra x chromosome of the patient. CONCLUSIONS: This report suggests that SHOX gene triplication may produce a tall stature, even in the presence of preserved ovarian function. X triplication might predispose to insulin resistance and behavioral disorders. ( info)

6/22. A case of 49,XXXXX in which the extra X chromosomes were maternal in origin.

    This report describes an 11 month old female baby with features of pentasomy X. A molecular and cytogenetic evaluation revealed that her karyotype was 49,XXXXX and her extra X chromosomes were of maternal origin. She has muscular hypotonia, mental retardation, a cleft palate, mild hydrocephalus as a result of dilatation of both lateral ventricles, hyperextensible elbow joints, proximal radioulnar synostosis, clinodactyly of the fifth finger, valgus of the feet, and small hands and feet. In addition, she has a persistent pupillary membrane and congenital chorioretinal atrophy. The pathogenesis of pentasomy X is not clear at present, but it is thought to be caused by successive maternal non-dysjunctions. ( info)

7/22. Functional disomy resulting from duplications of distal Xq in four unrelated patients.

    Duplications involving the x chromosome, in which the duplicated region is not subject to inactivation, are rare. We describe four distal Xq duplications, in three males and one female, in which the duplicated X chromosomal material is active in all cells. The infantile phenotype bears some resemblance to that of the prader-willi syndrome, presenting with initial feeding difficulties, hypotonia and, sometimes, with cryptorchidism. However, the severity of the phenotype is not simply related to the size of the duplication and so variations in gene expression, gene disruption or position effects from breakpoints should be considered as explanations. We have compared the clinical, cytogenetic and molecular findings of our patients with those previously reported. This has enabled us to question the suggestion that duplication of the gene SOX3 is the cause of hypopituitarism and that duplication of Filamin A is the cause of bilateral periventricular nodular heterotopia/mental retardation syndrome (BPNH/MR). We have also narrowed the putative critical interval for X-linked spina bifida. ( info)

8/22. HLHS with severe aortic insufficiency in a patient with 45,X/46,XY mosaicism.

    Aortic insufficiency is not a part of the hypoplastic left heart syndrome. This report describes a rare case of congenital aortic insufficiency from a detached leaflet in a patient with hypoplastic left heart syndrome and 45,X/46XY mosaicism. The patient was subsequently treated with the modified Norwood procedure along with suture closure of aortic valve. ( info)

9/22. 49, XXXXY syndrome.

    49, XXXXY syndrome is a rare sex chromosomal disorder. A 5-month-old boy had failure to thrive and multiple congenital anomalies including microcephaly, facial dysmorphism (hypertelorism, megacornea, cleft palate, and micrognathia), obvious heart murmur, umbilical hernia, microphallus, and mild clenched hands. Chromosomal studies via techniques of G-banding and fluorescence in situ hybridization showed the constitution to be 47, XXXXY in all cells. Ventriculomegaly and congenital cardiac defects (patent ductus arteriosus, atrial septal defect, and peripheral pulmonary stenosis) were noted. He has severe atopic dermatitis with high IgE levels and psychomotor retardation. After heart surgery and nutritional support, he has better growth and the rehabilitation program is continuing. ( info)

10/22. Analysis of SRY gene in 8 cases of sex abnormality.

    In order to investigate the relationship between sex dysplasia and sex-determining region Y (SRY) gene, 8 patients with sexual abnormality were analyzed by cytogenetic and molecular genetic methods. fluorescence in situ hybridization (FISH) using PY3.4, X alpha satellite, and SRY probes was performed in each case to analyze the sex chromosome translocation and gene translocation. SRY gene was amplified by polymerase chain reaction (PCR) and its mutation was detected by direct sequencing. The results showed that among 8 patients, 5 were positive for SRY and the remaining negative for SRY. In the patients positive for SRY genes, 3 presented testes and the left 2 streak ovaries. In the patients negative for SRY, only one case presented testes, while 2 ovaries. Direct sequencing demonstrated that all SRY genes were normal in the patients positive for SRY genes. FISH technique demonstrated that SRY genes translocated from Ypter to Xpter in 2 46,XX phenotypic males positive for SRY genes. It was concluded that SRY gene is strongly involved in male sex determination, while a sequence of other genes may be taken into account in sexual development. ( info)
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