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PubMed1997

[ORL and speech aspects in DiGeorge syndrome].

The DiGeorge syndrome presents clinically as a combination of a congenital cardiopathy with immune deficiency and predisposition to infections, signs of hypoparathyroidis with severe hypocalcaemia in the neonatal period, and facial dysmorphism. New techniques in molecular cytogenetics (in-situ fluorescent hybridisation--FISH) have provided evidence of microdeletion of chromosome 22q11 in most cases of the DiGeorge syndrome. There is an important overlap between this syndrome, the velo-cardio-facial syndrome, and certain other cono-truncal cardiac anomalies which are linked with the same microdeletion syndrome. Basing their observation on a case of the partial syndrome, the authors emphasise the otological and maxillo-facial aspects, and especially the effects on speech and language. It is essential to carry out repeated audiometric testing to exclude an audiometric cause for the speech and language problems. At the same time, thorough speech and language assessment is necessary to establish the degree of velar insufficiency (rhinolalia). These will guide the speech therapy rehabilitation, and quantify the psycho-affective component. Surgery on the palate may be a possibility, depending on the progress in speech and language improvement.

DiGeorge Syndrome↗
PubMed1998

Submicroscopic deletion of chromosome 16p13.3 in patients with Rubinstein-Taybi syndrome.

The Rubinstein-Taybi syndrome (RTS) is a well-defined entity characterized by growth and mental retardation, broad thumbs and halluces, and typical face. The RTS locus was assigned to 16p13.3, and interstitial submicroscopic deletions of this region (RT1 cosmid, D16S237) were initially identified in 25% of RTS patients. The gene for the human CREB binding protein, the transcriptional coactivator CBP, is included in the RT1 cosmid, and mutations in CBP have recently been identified in nondeleted RTS patients. We investigated 30 French patients with RTS. Among these patients, 3 had the RT1 microdeletion (frequency 10%). There is no obvious phenotypic difference between the patients with and without the RT1 deletion. The RT1 probe appears useful for confirmation of the diagnosis but is of little interest as a screening tool. By pooling data including the previous series and our current series, the cumulative frequency of the 16p13.3 microdeletion is 11.9% (19 in 159). This frequency of approximately 12% deleted patients appears more accurate than the 25% previously reported. Molecular investigations of CBP are in process in our series to clarify the cause of RTS.

CREB-Binding Protein↗
PubMed1998

Genetic concerns for the subfertile male in the era of ICSI.

The treatment of severe male factor infertility has seen remarkable advances in the last five years with the introduction and widespread use of intracytoplasmic sperm injection (ICSI). Although ICSI represents one of the most important advances in the treatment of the subfertile male, significant concerns exist regarding the potential for transmission of abnormal genes to the offspring because many of the natural barriers to conception have been bypassed. Because these couples were not able to conceive prior to ICSI, the long-term genetic consequences in these offspring are largely undefined at this time. Genetic abnormalities related to male infertility need to be considered in terms of being (1) causative for male infertility and (2) potentially transmissible to the offspring. Reasons for pursuing a genetic evaluation include (1) establishing a diagnosis, (2) establishing a possible genetic origin, (3) clarifying the pattern of inheritance, and (4) providing information on natural history, variation and expression. The three most common known genetic factors related to male infertility are cystic fibrosis gene mutations leading to congenital absence of the vas deferens, Y-chromosome microdeletions leading to spermatogenic impairment, and karyotype abnormalities. When congenital bilateral absence of the vas deferens with azoospermia is encountered, cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations are commonly the underlying cause. When testicular failure is manifest by azoospermia or severe oligoszoospermia, Y-chromosome microdeletions may be present in approximately 10-15 per cent of otherwise normal appearing men. Karyotyping can uncover potentially transmissible genetic abnormalities in the infertile male including structural chromosomal disorders such as Klinefelter's (classic 47,XXY), mixed gonadal dysgenesis, chromosomal translocations and XYY syndromes. Finally, potential male infertility genes in animal models are reviewed. Without question, advances in clinical and basic research raise scientific and social issues that must be addressed.

Animals↗
PubMed1999

Functional evidence of novel tumor suppressor genes for cutaneous malignant melanoma.

Losses of heterozygosity involving chromosomes 9 and 10 are frequent events in the development and progression of cutaneous malignant melanoma. To investigate whether specifically deleted chromosomal regions encode tumor suppressor genes (TSGs), we introduced normal chromosome 10 into the tumorigenic human metastatic melanoma cell line UACC-903 by microcell fusion. In addition, two chromosome 9 derivatives that were microdeleted in the region of the p16INK4A/p15INK4B locus were transferred to determine whether an additional melanoma TSG or TSGs reside on chromosome 9p, as indicated by previous melanoma allele loss studies. In comparison to parental cells, microcell hybrids generated with chromosomes 9 (microdeleted) and 10 displayed reduced anchorage-independent growth in soft agar and markedly reduced tumorigenicity in athymic (nu/nu) mice. These data define a TSG or TSGs that function independently of p15/p16 on chromosome 9 and provide evidence for a TSG (or TSGs) on chromosome 10 that may be important in melanoma development.

Agar↗
PubMed2001

Hereditary neuropathy with liability to pressure palsies is not a major cause of idiopathic carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome is a debilitating neuropathy affecting millions of individuals. Although there are published reports of familial associations of carpal tunnel syndrome, the molecular mechanisms are unknown. OBJECTIVE: To determine the prevalence and potential role of the chromosome 17 microdeletion associated with hereditary neuropathy with liability to pressure palsies in patients diagnosed as having carpal tunnel syndrome. DESIGN: Prospective study. PATIENTS AND METHODS: Since hereditary neuropathy with liability to pressure palsies may present as carpal tunnel syndrome, we evaluated 50 patients with idiopathic carpal tunnel syndrome for hereditary neuropathy with liability to pressure palsies. RESULTS: No hereditary neuropathy with liability to pressure palsies deletions were detected. CONCLUSION: Molecular genetic testing for hereditary neuropathy with liability to pressure palsies in patients with idiopathic carpal tunnel syndrome is of limited value.

Adult↗
PubMed2001

A family with X-linked dystonia-deafness syndrome with a novel mutation of the DDP gene.

BACKGROUND: X-linked dystonia-deafness syndrome (DDS) is characterized by early-onset deafness followed by progressive dystonia in adulthood. Only 4 families with the syndrome have been reported, and all were white. OBJECTIVE: To describe the first nonwhite family with X-linked DDS, involving 5 affected males in 4 generations. RESULTS: Clinical features of the family members, who were Japanese, were mostly consistent with reports of DDS in whites except for a lack of visual disturbances. Whereas microdeletions in the deafness-dystonia peptide (DDP) gene were found in 2 white DDS families, our patients showed a novel mutation (arg80ter) in exon 2 of the DDP gene. CONCLUSION: The existence of a DDS family of Japanese origin with a new kind of mutation in the DDP gene provides additional evidence that the DDP gene is a causative gene for X-linked DDS.

Adolescent↗
PubMed2000

Velocardiofacial syndrome: incidence of immune cytopenias.

BACKGROUND: Velocardiofacial syndrome (VCFS) is associated with a broad clinical spectrum that frequently overlaps the DiGeorge syndrome. Both have been linked to chromosomal microdeletions of chromosome 22 (22q11.2). DiGeorge syndrome is associated with T-cell dysfunction. What is the incidence of immune cytopenias in children with VCFS? OBJECTIVES: To (1) identify, (2) characterize, (3) quantify, and (4) follow up the immunologic deficits in children initially seen in our institution with VCFS. DESIGN: Prospective clinical evaluation of patients with the features of VCFS. PATIENTS: Twenty consecutive children with the clinical diagnoses of VCFS. SETTING: Tertiary care children's hospital. MAIN OUTCOME MEASURES: All 20 children had genetics evaluation with chromosomal analysis. Immunologic evaluations included serum immunoglobulin concentrations, lymphocyte studies, and mitogen and antigen stimulation studies. RESULTS: Five (25%) of 20 children were noted to have T-cell dysfunction with a clinical presentation marked by recurrent upper respiratory tract infections. Three of these 5 children had resolution of the T-cell dysfunction over a 2-year period. The 2 children with persistent cytopenias combined with immunoglobulin dysfunction required intravenous IgG infusions to control their infections. CONCLUSIONS: Velocardiofacial syndrome is associated with an increased incidence of immune cytopenias and, thus, warrants evaluation in any child with the clinical diagnosis of VCFS. This immune deficit may be transient and depends on the age of the evaluation of the child.

Child, Preschool↗
PubMed1998

Deletion 22q11: a newly recognized cause of behavioral and psychiatric disorders.

BACKGROUND: Chromosome 22q11 deletion (del22q11), the most common microdeletion syndrome, causes a wide spectrum of clinical disorders. Recent studies have suggested that significant psychiatric and behavioral disturbances occur in up to 60% of these individuals. OBJECTIVE: To illustrate the spectrum of behavioral and psychiatric abnormalities associated with del22q11 and the subtle nature of its associated physical findings. PATIENTS AND METHODS: Case series describing psychiatric and behavioral findings in 3 patients with del22q11. RESULTS AND CONCLUSIONS: Behavioral and psychiatric problems are common in patients with del22q11 syndrome. Because the physical manifestations of the disorder are so variable and may be subtle, the behavioral and psychiatric manifestations may be the presenting problem. Providers must therefore consider del22q11 as a potential diagnosis in children and adults with behavioral and psychiatric problems. Furthermore, behavioral and psychiatric problems need to be looked for when caring for children and adolescents with a known diagnosis of del22q11.

Adolescent↗
PubMed1993

Velo-cardio-facial syndrome. Intrafamilial variability of the phenotype.

We describe a mother and son with velo-cardio-facial syndrome (VCFS) in whom cytogenetic and DNA molecular studies demonstrate an interstitial deletion of the long arm of chromosome 22. Although these two individuals manifest the typical facial and cognitive features of VCFS, they are discordant for the cardiovascular and palatal anomalies, which are seminal manifestations of the disorder. Previously, this degree of phenotypic variability had not been well appreciated within a single family segregating the VCFS deletion. A review of other familial cases of VCFS suggests that the family described in this article is not atypical. Because a microdeletion would be expected to be inherited without alteration within individual families, the phenotypic variability observed in these families appears to be an intrinsic quality of the syndrome and not wholly due to genetic heterogeneity.

Abnormalities, Multiple↗
PubMed1997

Screening the monoamine oxidase B gene in 100 male patients with schizophrenia: a cluster of polymorphisms in African-Americans but lack of functionally significant sequence changes.

The monoamine oxidase B (MAO-B) gene was examined in 100 alleles derived from 80 Caucasian, 10 African-American, 5 Asian, and 5 Native American male patients with schizophrenia to identify sequence changes that might be associated with the disease. Approximately 235 kb of genomic sequence, primarily in coding regions, were screened by dideoxy fingerprinting, a modification of single-strand conformational polymorphism (SSCP) analysis that detects virtually 100% of sequence changes [Sarkar et al. (1992): Genomics 13:441-443; Liu and Sommer (1994): PCR Methods Appl 4:97-108]. No sequence changes of likely functional significance were identified, suggesting that mutations affecting the structure of the MAO-B protein are uncommon in the general population and are unlikely to contribute significantly to the genetic predisposition to schizophrenia. Eight polymorphisms were identified in African-Americans and Native Americans, but none were identified among Caucasians. Of the eight observed polymorphisms, a set of five transitions and one microdeletion was identified within approximately 17 kb of genomic sequence in the same 3 African-American individuals, while the remaining 7 African-Americans had a sequence identical to that in Caucasians. The presence of two such haplotypes, without intermediates, is compatible with the hypothesis that germline mutations can occur in clusters, as also suggested by other recent findings.

Black People↗
PubMed1997

Linkage studies suggest a possible locus for bipolar disorder near the velo-cardio-facial syndrome region on chromosome 22.

Velo-cardio-facial syndrome (VCFS) is a congenital anomaly characterized by multiple dysmorphisms, cleft palate, cardiac anomalies, and learning disabilities, that results from a microdeletion of chromosome 22q11. An increased prevalence of psychiatric illness has been observed, with both schizophrenia and bipolar disorder commonly being diagnosed. For these reasons, the VCFS region is an interesting candidate region for bipolar disorder. We examined this region in 17 bipolar families from three populations: 13 families from the general North American population (University of California, San Diego/University of British Columbia, UCSD/UBC), three larger families from New York, and a portion of Old Order Amish pedigree 110. Three microsatellite markers spanning 13 cM around the VCFS region were genotyped in all the families. A maximum lod score of 2.51 was obtained in the UCSD/UBC families under a dominant model at D22S303. In the combined family set, maximum lod scores of 1.68 and 1.28 were obtained at this marker under dominant and recessive models, respectively. Four additional markers were subsequently typed in selected positive families, and yielded positive lods at 6 of 7 markers spanning 18 cM in this region. Nonparametric, multipoint analyses using the affected pedigree member (APM) method also yielded suggestive evidence for linkage in both the UCSD/UBC family set (P = 0.0024) and in the combined families (P = 0.017). Affected sibpair analyses were similarly positive in the UCSD/UBC families (P = 0.017), and in the combined families (P = 0.004). These results are suggestive of a possible locus for bipolar disorder near the VCFS region on chromosome 22.

Abnormalities, Multiple↗
PubMed1998

Kenny-Caffey syndrome and microorchidism.

We report on two adolescent boys with Kenny-Caffey syndrome and microorchidism. The first patient had elevated levels of serum follicle-stimulating hormone, but normal levels of luteinizing hormone and testosterone. There was no evidence of a microdeletion of the Y chromosome. The second patient had Leydig cell hyperplasia with normal seminiferous tubules and spermatogenesis, and normal pituitary histologic findings at autopsy. The presence of microorchidism in these patients confirms the previous observations and suggests subfertility, but does not fully clarify the pathogenesis.

Abnormalities, Multiple↗
PubMed1998

Submicroscopic deletion in 14q32.3 through a de novo tandem translocation between 14q and 21p.

We describe a male child with craniofacial anomalies, postnatal onset growth retardation, microcephaly, multiple minor anomalies, hearing loss, and moderate delay of mental and statomotor development. He carries a previously undescribed tandem translocation between the long arm of chromosome 14 and the short arm of chromosome 21 that arose de novo. As proven by fluorescence in situ hybridization a microdeletion not detectable with high-resolution G-banding occured in 14q32.3, the terminal band on the long arm of chromosome 14. The resulting phenotype includes most abnormalities encountered in patients with terminal 14q32.3 deletions but in addition includes some characteristics of the ring chromosome 14 syndrome.

Abnormalities, Multiple↗
PubMed1999

Persistent truncus arteriosus in monozygotic twins: case report and literature review.

We report on a pair of monozygotic twins with persistent truncus arteriosus. They had no evident clinical signs of DiGeorge syndrome. Pathologic examination of the placenta and DNA analysis in chromosomes 7, 8, and 15 was consistent with monozygosity. Fluorescence in situ hybridization test was negative for chromosome 22q11 microdeletion. Family history revealed a female cousin with tetralogy of Fallot. The isolated presence of this conotruncal abnormality in monozygotic twins is extremely rare. The genetic considerations are discussed.

Diseases in Twins↗
PubMed1999

Costello syndrome: report and review.

We describe a 34-year-old woman with mental retardation, short stature, macrocephaly, a "coarse" face, hoarse voice, and redundant skin with deep palmar and plantar creases who had evident Costello syndrome. Lacking papillomata, she had wart-like lesions of the skin. The previously reported patients with Costello syndrome are reviewed. Costello syndrome is probably an autosomal dominant disorder, either caused by a mutation in a single gene or by microdeletion.

Abnormalities, Multiple↗
PubMed1999

Microcephaly with simplified gyral pattern in six related children.

We describe clinical and neurophysiological findings in six related children with congenital microcephaly, seizures that began within the first 2-4 months of life, and severe mental retardation (MR). These affected children (five girls and one boy), born to two women who are half-sisters, inherited the disease as an autosomal recessive trait. Physical examination of these children did not show any of the anomalies in the known cortical malformation syndromes such as lissencephaly types I and II. Neuroradiological studies in these children documented microcephaly and a simplified gyral pattern with no pachygyria. Chromosomal analysis showed neither karyotypic abnormalities nor a microdeletion at 17p13.3, site of the lissencephaly type I gene locus (LIS1). Genetic studies failed to show linkage of this family to LIS1, LIS2 (a region on chromosome 2p homologous to LIS1), or MCPH1 (a locus for primary autosomal recessive microcephaly). The unique clinical and genetic findings in this family suggest that these children may be affected by an as-of-yet unmapped neuronal proliferation disorder.

Adolescent↗
PubMed1999

Guidelines for buccal smear collection in breast-fed infants.

Buccal smear analysis is a noninvasive, fast, and relatively inexpensive diagnostic method. It is used commonly where rapid gender identification is necessary or, more recently, for detection of aneusomy, microdeletion syndromes, and a variety of polymerase chain reaction-based molecular genetic tests. Previously we have shown that maternal cells can contaminate buccal smears taken from breast-fed infants, resulting in difficulty with test interpretation. The aim of this study was to determine optimal timing and technique for buccal smear collection in breast-fed infants in order to avoid diagnostic errors. We analyzed prospectively 50 breast-fed male infants for presence of cells with XX signal pattern from buccal mucosa scrapings at different times after breast feeding. The efficiency of mucosal cleaning on elimination of maternal cells was evaluated by comparing the proportion of XX cells before and after wiping of buccal mucosa with a cotton swab. Maternal cells were present in 23 of 48 (47.9%) samples collected within 5 min of feeding. The proportion of XX signal pattern was significantly (P = 0.001) reduced in samples collected at 30 min (8/48, P = 0.001) and > or =60 min (2/29, P = 0.0002) after feeding. Mucosal cleaning prior to smear collection significantly decreased the number of XX positive samples from 23 of 48 to 10 of 48 (P = 0.002). Buccal smears should not be obtained in nursing neonates until at least 60 min after breast feeding. In addition, prior to sample collection, buccal mucosa should be cleaned thoroughly with a cotton swab applicator. The same guidelines are applicable to older nursing infants.

Breast Feeding↗
PubMed1999

Health supervision and anticipatory guidance of individuals with Wolf-Hirschhorn syndrome.

Wolf-Hirschhorn syndrome (WHS) is a well-known malformation syndrome due to microdeletion of the short arm of chromosome 4 (4p-). Almost 120 cases have been reported so far, yet there is still limited information on its natural history. It is generally thought that these children have severe developmental disabilities and tend to be mere survivors devoid of personality. It is evident to us [Battaglia et al., 1999a, 1999b], however, that individuals with WHS are capable of greater psychomotor development than previously suggested [Guthrie et al., 1971]. Thus, it is even more important to establish guidelines for health supervision and anticipatory guidance of such patients. This would help professionals and families in developing the most appropriate individualized plan for each child, in order to allow the maximum achievement possible. In the present article we propose guidelines for health supervision and anticipatory guidance of individuals with WHS. These guidelines derive from our experience with the natural history of several children, adolescents, and adults with WHS, gained through the literature, personal observation, and contacts with the national support groups in North America and Italy.

Abnormalities, Multiple↗