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Kaye EM, Shalish C, Livermore J, Taylor HA, Stevenson RE, Breakefield XO. beta-Galactosidase gene mutations in patients with slowly progressive GM1 gangliosidosis. J Child Neurol 1997; 12:242-7. [PMID: 9203065 DOI: 10.1177/088307389701200404] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Three unrelated North American cases with slowly progressive forms of GM1 gangliosidosis were found to have two unique point mutations and a 9 bp insertion in the coding region of the gene encoding beta-galactosidase. Case 1 was noted to have a 9 bp insertion ¿CAGAATTTT¿ on one allele between nucleotides 730 and 731 with no other mutations identified in the other allele. In case 2, two point mutations were found: a unique G-->A transition at nucleotide 602 causing an Arg-->His substitution in codon 201 (mutation R201H); and a previously identified G-->T transition at nucleotide 1527 causing a Trp-->Cys substitution in codon 509 (mutation W509C), which has been noted in adult and chronic forms of GM1 gangliosidosis. Case 3 had a unique point mutation (A-->G transition at nucleotide 797) resulting in a Asn-->Ser amino acid substitution in codon 266 (mutation N266S), with no other mutations found in the same or the other allele. Single-strand conformation polymorphism performed on over 100 controls did not demonstrate the presence of the point mutations R201H or N266S. Also, the mutant proteins coded by the two point mutations did not show enzymatic activity in the Cos-1 cell expression system confirming that these mutations are associated with low enzyme activity.
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Stevenson RE, Schwartz CE, Du YZ, Adams MJ. Differences in methylenetetrahydrofolate reductase genotype frequencies, between Whites and Blacks. Am J Hum Genet 1997; 60:229-30. [PMID: 8981967 PMCID: PMC1712549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Häne B, Schroer RJ, Arena JF, Lubs HA, Schwartz CE, Stevenson RE. Nonsyndromic X-linked mental retardation: review and mapping of MRX29 to Xp21. Clin Genet 1996; 50:176-83. [PMID: 9001795 DOI: 10.1111/j.1399-0004.1996.tb02622.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The gene responsible for nonsyndromic mental retardation in a family with 7 affected males has been localized to Xp21. The maximal two-point lod score was 3.31 for tight linkage to marker DXS1202 in Xp21.3-p22.3 with crossovers between the 3' portion of the DMD gene (DXS1234) proximally and locus DXS989 distally. The XLMR gene in this family has been assigned the designation MRX29. The localization overlaps with at least six other MRX entities linked to the distal short arm of the X chromosome.
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Lubs HA, Schwartz CE, Stevenson RE, Arena JF. Study of X-linked mental retardation (XLMR): summary of 61 families in the Miami/Greenwood Study. AMERICAN JOURNAL OF MEDICAL GENETICS 1996; 64:169-75. [PMID: 8826469 DOI: 10.1002/(sici)1096-8628(19960712)64:1<169::aid-ajmg29>3.0.co;2-k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The initial goal of this study was to localize as many genes as possible that lead to syndromic and nonspecific XLMR. More recently, this goal has been redefined to include narrowing these localizations and cloning specific genes. In the last 5 years, 61 families have participated in this study; 34 have a projected or actual lod score greater than 2.0. Restudy of 12 families reported previously has been a particularly productive aspect of this study and has led to clinical redefinition and new or improved localization of most of these syndromes. Five possible new XLMR syndromes have been identified. Five large families with nonspecific XLMR have been regionally localized. Since many XLMR conditions are based on only 1 or 2 family reports, one of the major purposes of this summary is to provide clinical data on the study families so that collaborative projects can be undertaken with other centers that have similar families.
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Ou CY, Stevenson RE, Brown VK, Schwartz CE, Allen WP, Khoury MJ, Rozen R, Oakley GP, Adams MJ. 5,10 Methylenetetrahydrofolate reductase genetic polymorphism as a risk factor for neural tube defects. AMERICAN JOURNAL OF MEDICAL GENETICS 1996; 63:610-4. [PMID: 8826441 DOI: 10.1002/(sici)1096-8628(19960628)63:4<610::aid-ajmg15>3.0.co;2-l] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Persons with a thermolabile form of the enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) have reduced enzyme activity and increased plasma homocysteine which can be lowered by supplemental folic acid. Thermolability of the enzyme has recently been shown to be caused by a common mutation (677C-->T) in the MTHFR gene. We studied 41 fibroblast cultures from NTD-affected fetuses and compared their genotypes with those of 109 blood specimens from individuals in the general population. 677C-->T homozygosity was associated with a 7.2 fold increased risk for NTDs (95% confidence interval: 1.8-30.3; p value: 0.001). These preliminary data suggest that the 677C-->T polymorphism of the MTHFR gene is a risk factor for spina bifida and anencephaly that may provide a partial biologic explanation for why folic acid prevents these types of NTD.
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Stevenson RE, Massey PS, Schroer RJ, McDermott S, Richter B. Preventable fraction of mental retardation: analysis based on individuals with severe mental retardation. MENTAL RETARDATION 1996; 34:182-188. [PMID: 8684286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Reduction in the prevalence of mental retardation has been identified as a national goal since 1971. President Nixon proposed the year 2000 as a benchmark, by which time the prevalence of severe mental retardation should be reduced by as much as 50%. An analysis to determine the fraction of severe mental retardation that could be prevented with strategies currently available indicates that the goal will not be met. Knowledge of the causes of severe mental retardation is fundamental to developing prevention strategies. Increased diagnostic capability-clinical and laboratory-must be dramatically increased if a 50% reduction in the prevalence of severe mental retardation is to be achieved in the foreseeable future.
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Abstract
Active and passive surveillance methods were utilized in an attempt to identify all neural tube defect (NTD)-affected pregnancies in South Carolina, a state previously identified to have a high prevalence of these defects (Greenberg et al., 1983). Sources of case ascertainment included maternal serum alpha-fetoprotein (MSAFP) programmes, prenatal diagnosis (amniocentesis) programmes, physician offices, perinatal centres, hospital medical record departments, and vital records. One hundred and nine NTD cases were identified over 24 months, indicating a prevalence of 1.60 cases per 1000 recorded births and fetal deaths (surveillance 1 October 1992-30 September 1994). Fifty-three (49 per cent) of the 109 NTD-affected pregnancies were either spontaneously or electively aborted prior to 26 weeks' gestation. Only three (6 per cent) of these early termination NTD cases were recorded in vital records, while medical records recorded 40 cases (75 per cent). By monitoring MSAFP programmes and maintaining frequent contact with physician offices and perinatal centres, 85 per cent of these early termination NTD-affected pregnancies were identified. However, for complete ascertainment of NTD-affected pregnancies, the utilization of all of these ascertainment methods was necessary, as each ascertainment method identified NTD cases missed by the other methods. Consideration of the significant impact of prenatal diagnosis on NTD surveillance and the use of multiple ascertainment methods in an attempt at complete ascertainment is particularly important now because of the recent recommendation for the periconceptional use of folic acid to prevent neural tube defects and the need for epidemiological studies to monitor the effectiveness of this prevention.
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Davis BA, Bailey LB, Gregory JF, Toth JP, Dean J, Stevenson RE. Folic acid absorption in women with a history of pregnancy with neural tube defect. Am J Clin Nutr 1995; 62:782-4. [PMID: 7572709 DOI: 10.1093/ajcn/62.4.782] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Folic acid absorption was compared in nonpregnant women with a history of pregnancy with a neural tube defect (cases)(n = 10) with that of control women (n = 10) with a normal pregnancy history. [2H4]folic acid was administered in an oral dose (400 micrograms) to fasting case and control subjects after a 30-d saturation protocol involving daily ingestion of two 1-mg folic acid supplements. Serum and red blood cell folate concentrations were not different for case and control subjects before or during the saturation protocol (P > 0.05). The percentage (x +/- SD) of the oral dose of [2H4]folic acid excreted in 24-h urine collections postdose was not different (P > 0.05) for case compared with control subjects (9.05 +/- 2.25% and 11.10 +/- 3.41%, respectively). These data suggest that the absorption of folic acid routinely consumed in supplements and fortified food products is not impaired in women with a history of a pregnancy with a neural tube defect. Further case-controlled studies are needed to compare the absorption of the predominant dietary form of the vitamin.
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Cragan JD, Roberts HE, Edmonds LD, Khoury MJ, Kirby RS, Shaw GM, Velie EM, Merz RD, Forrester MB, Williamson RA, Krishnamurti DS, Stevenson RE, Dean JH. Surveillance for anencephaly and spina bifida and the impact of prenatal diagnosis--United States, 1985-1994. MMWR. CDC SURVEILLANCE SUMMARIES : MORBIDITY AND MORTALITY WEEKLY REPORT. CDC SURVEILLANCE SUMMARIES 1995; 44:1-13. [PMID: 7637675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PROBLEM/CONDITION The reported prevalence of anencephaly and spina bifida in the United States has steadily declined since the late 1960s. During this time, the ability to diagnose these defects prenatally has progressed rapidly. Many U.S. birth defects surveillance systems ascertain defects only among live-born infants or among infants and fetuses beyond a certain gestational age, thus excluding defects among pregnancies prenatally diagnosed as being affected by a neural tube defect (NTD) and electively terminated before the gestational age limit. The impact of prenatal diagnosis and subsequent pregnancy termination on the reported prevalence of anencephaly and spina bifida in the United States has not been well established. However, assessment of this impact is crucial to the use of surveillance data to monitor trends in the occurrence of NTDs and the effectiveness of interventions for these defects (e.g., increased consumption of folic acid). REPORTING PERIOD This report presents data from birth defects surveillance systems in six states over different time periods: Arkansas, 1985-1989; California, 1989-1991; Georgia, 1990-1991; Hawaii, 1988-1994; Iowa, 1985-1990; and South Carolina, 1992-1993. DESCRIPTION OF SYSTEMS Population-based data about a) live-born and stillborn infants with anencephaly and spina bifida and b) pregnancies electively terminated after prenatal diagnosis of these defects were analyzed from the Arkansas Reproductive Health Monitoring System; the California Birth Defects Monitoring Program; CDC's Metropolitan Atlanta Congenital Defects Program; the Iowa Birth Defects Registry, the University of Iowa, and the Iowa Department of Public Health; and the Greenwood Genetic Center in South Carolina. Data also were analyzed from the Hawaii Birth Defects Monitoring Program, which includes data for some women who were not residents of the state. The systems differed in the size and racial/ethnic composition of the populations studied, the surveillance methods used, the completeness of ascertainment, and the availability and utilization of prenatal testing and pregnancy termination. RESULTS AND INTERPRETATION Among all pregnancies ascertained in which the infant or fetus had anencephaly or spina bifida, the percentages that were electively terminated ranged from 9% in Arkansas to 42% in Atlanta and Hawaii, with a corresponding increase in the adjusted prevalence of these defects compared with the prevalence at birth. In each system, pregnancies associated with anencephaly were terminated more frequently than were those associated with spina bifida. These data indicate that the impact of prenatal diagnosis and subsequent pregnancy termination on the prevalence at birth of anencephaly and spina bifida differs among geographic areas and populations. Comprehensive surveillance for these defects requires inclusion of pregnancies that are prenatally diagnosed and then terminated. ACTIONS TAKEN CDC will use these data to promote the inclusion of prenatally diagnosed and terminated pregnancies in estimates of the prevalence of anencephaly and spina bifida generated by birth defects surveillance programs in the United States. Including such pregnancies is crucial to the ability of these programs to monitor trends accurately and to establish the effectiveness of interventions, including the use of folic acid, for these defects.
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Adams MJ, Khoury MJ, Scanlon KS, Stevenson RE, Knight GJ, Haddow JE, Sylvester GC, Cheek JE, Henry JP, Stabler SP. Elevated midtrimester serum methylmalonic acid levels as a risk factor for neural tube defects. TERATOLOGY 1995; 51:311-7. [PMID: 7482352 DOI: 10.1002/tera.1420510507] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The role of folic acid in the primary prevention of neural tube defects (NTDs) is well established. However, questions related to the protective mechanism remain unanswered. To help answer these questions, we designed a case-control study to assess the role of folate- and cobalamin-related metabolites in the pathogenesis of NTDs. Concentrations of folate, cobalamin, and 14 other related metabolites were measured by gas chromatography/mass spectrometry in midtrimester serum specimens from 32 women with an NTD-affected pregnancy and from 132 control women, and in serum specimens from 46 nonpregnant women who had a history of NTD-affected pregnancy and from 43 nonpregnant control women. Log-transformed means of metabolites were compared between case and control women for both the midtrimester and nonpregnant groups. In the pregnant group, serum methylmalonic acid (MMA) concentrations were higher among case women than among control women (130 vs 105 nM). There was a strong dose-response relationship between midtrimester serum MMA level and the risk for an NTD-affected pregnancy, with the relative risk increasing 13-fold for women with MMA levels > 90th percentile. In the nonpregnant group, there was no difference in serum MMA levels between case and control women (140 vs 140 nM). Thus, the serum MMA levels of women in the midtrimester of pregnancies unaffected by NTDs were significantly lower than the levels of nonpregnant women, whereas the levels of women whose pregnancies were affected by NTDs were similar to those of nonpregnant women. The finding of elevated MMA serum concentrations among women in the midtrimester of NTD-affected pregnancies suggests that cobalamin may be involved in the etiology of NTDs. The possible role of cobalamin in relation to the protective effect of folic acid needs further evaluation.
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Tranebjaerg L, Schwartz C, Eriksen H, Andreasson S, Ponjavic V, Dahl A, Stevenson RE, May M, Arena F, Barker D. A new X linked recessive deafness syndrome with blindness, dystonia, fractures, and mental deficiency is linked to Xq22. J Med Genet 1995; 32:257-63. [PMID: 7643352 PMCID: PMC1050371 DOI: 10.1136/jmg.32.4.257] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
X linked recessive deafness accounts for only 1.7% of all childhood deafness. Only a few of the at least 28 different X linked syndromes associated with hearing impairment have been characterised at the molecular level. In 1960, a large Norwegian family was reported with early onset progressive sensorineural deafness, which was indexed in McKusick as DFN-1, McKusick 304700. No associated symptoms were described at that time. This family has been restudied clinically. Extensive neurological, neurophysiological, neuroradiological, and biochemical, as well as molecular techniques, have been applied to characterise the X linked recessive syndrome. The family history and extensive characterisation of 16 affected males in five generations confirmed the X linked recessive inheritance and the postlingual progressive nature of the sensorineural deafness. Some obligate carrier females showed signs of minor neuropathy and mild hearing impairment. Restudy of the original DFN-1 family showed that the deafness is part of a progressive X linked recessive syndrome, which includes visual disability leading to cortical blindness, dystonia, fractures, and mental deficiency. Linkage analysis indicated that the gene was linked to locus DXS101 in Xq22 with a lod score of 5.37 (zero recombination). Based on lod-1 support interval of the multipoint analysis, the gene is located in a region spanning from 5 cM proximal to 3 cM distal to this locus. As the proteolipid protein gene (PLP) is within this region and mutations have been shown to be associated with non-classical PMD (Pelizaeus-Merzbacher disease), such as complex X linked hereditary spastic paraplegia, PLP may represent a candidate gene for this disorder. This family represents a new syndrome (Mohr-Tranebjaerg syndrome, MTS) and provides significant new information about a new X linked recessive sydromic type of deafness which was previously thought to be isolated deafness.
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Marinoni JC, Stevenson RE, Evans JP, Geshuri D, Phelan MC, Schwartz CE. Split foot and developmental retardation associated with a deletion of three microsatellite markers in 7q21.2-q22.1. Clin Genet 1995; 47:90-5. [PMID: 7606850 DOI: 10.1111/j.1399-0004.1995.tb03930.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A deletion of 7q21.2-q22.1 has been found in a patient with split foot and developmental retardation. Molecular analysis using polymerase chain reaction (PCR) showed deletion of three microsatellite markers, D7S527, D7S479 and D7S554, in the patient's paternal chromosome. These results pinpoint the critical region for an ectrodactyly locus (SHFD1) on chromosome 7.
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Pasteris NG, Cadle A, Logie LJ, Porteous ME, Schwartz CE, Stevenson RE, Glover TW, Wilroy RS, Gorski JL. Isolation and characterization of the faciogenital dysplasia (Aarskog-Scott syndrome) gene: a putative Rho/Rac guanine nucleotide exchange factor. Cell 1994; 79:669-78. [PMID: 7954831 DOI: 10.1016/0092-8674(94)90552-5] [Citation(s) in RCA: 246] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Faciogenital dysplasia (FGDY), also known as Aarskog-Scott syndrome, is an X-linked developmental disorder characterized by disproportionately short stature and by facial, skeletal, and urogenital anomalies. Molecular genetic analyses mapped FGDY to chromosome Xp11.21. To clone this gene, YAC clones spanning an FGDY-specific translocation breakpoint were isolated. An isolated cDNA, FGD1, is disrupted by the breakpoint, and FGD1 mutations cosegregate with the disease. FGD1 codes for a 961 amino acid protein that has strong homology to Rho/Rac guanine nucleotide exchange factors (GEFs), contains a cysteine-rich zinc finger-like region, and, like the RasGEF mSos, contains two potential SH3-binding sites. These results provide compelling evidence that FGD1 is responsible for FGDY and suggest that FGD1 is a Rho/RacGEF involved in mammalian development.
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Stevenson RE, May M, Arena JF, Millar EA, Scott CI, Schroer RJ, Simensen RJ, Lubs HA, Schwartz CE. Aarskog-Scott syndrome: confirmation of linkage to the pericentromeric region of the X chromosome. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 52:339-45. [PMID: 7810566 DOI: 10.1002/ajmg.1320520317] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Aarskog-Scott syndrome was tentatively mapped to Xq13 on the basis of an X:8 translocation by Bawle et al. [Am J Med Genet 17:595-602, 1984]. A review of the cytogenetics and the use of molecular markers in that family have resulted in revision of the breakpoints of the translocation to Xp 11.2 and 8q11.21 [Glover et al., Hum Mol Genet 2:1717-1718, 1993]. Two families, including one of the two initial families with Aarskog-Scott syndrome [Scott, BD:OAS VII (6): 240-246, 1971], have participated in our study to evaluate the localization of the gene for Aarskog-Scott syndrome to the pericentromeric region of the X chromosome. Using a series of DNA probes, we have been able to confirm linkage to the X chromosome, with multipoint analysis indicating the most likely localization of the gene to be on the proximal short arm.
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Schwartz CE, Dean J, Howard-Peebles PN, Bugge M, Mikkelsen M, Tommerup N, Hull C, Hagerman R, Holden JJ, Stevenson RE. Obstetrical and gynecological complications in fragile X carriers: a multicenter study. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 51:400-2. [PMID: 7943006 DOI: 10.1002/ajmg.1320510419] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have conducted a multicenter obstetrical and gynecological survey of women in fragile X families. Included in the study were 131 gene carriers (39 with a full mutation and 92 with a premutation) and 109 noncarriers. Analysis indicated that higher numbers of fragile X gene carriers reported having irregular menses and other gynecological complications. As a group they also experienced cessation of menses prior to age 40 years at a significantly higher rate. The data appear to indicate that the FMR1 gene may play a role in the development and proliferation of oogonia.
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Stevenson RE, Schwartz CE, Arena JF, Lubs HA. X-linked mental retardation: the early era from 1943 to 1969. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 51:538-41. [PMID: 7943037 DOI: 10.1002/ajmg.1320510450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Wang Y, Treat K, Schroer RJ, O'Brien JE, Stevenson RE, Schwartz CE. Localization of branchio-oto-renal (BOR) syndrome to a 3 Mb region of chromosome 8q. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 51:169-75. [PMID: 8092198 DOI: 10.1002/ajmg.1320510221] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Branchio-oto-renal (BOR) syndrome is an autosomal dominant condition of branchial arch anomalies, deafness and renal dysplasia. Clinical manifestations tend to have considerable intrafamilial and interfamilial variability. Previous linkage studies had localized the gene responsible for BOR syndrome to a broad region of chromosome 8q. Using 10 microsatellite markers, we have further refined the localization of this disorder by establishing tight linkage to two markers, D8S279 and D8S530 (Zmax = 3.91 and Zmax = 2.83 respectively at theta = 0.00). These markers are within 1 cM of one another. Multipoint analysis, involving 7 loci, placed the gene between these markers, with a lod-1 confidence interval 0.7 cM proximal to D8S530 and 0.6 cM distal to D8S279.
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Saul RA, Rogers RC, Phelan MC, Stevenson RE. Brachmann-de Lange syndrome: diagnostic difficulties posed by the mild phenotype. AMERICAN JOURNAL OF MEDICAL GENETICS 1993; 47:999-1002. [PMID: 8291544 DOI: 10.1002/ajmg.1320470712] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We describe 4 patients with facial changes of Brachmann-de Lange syndrome but without limb defects. Mental retardation ranged from moderate to severe and the degree of prenatal and postnatal growth deficiency was variable. These patients exemplify the diagnostic difficulties and counseling dilemmas posed by the mild Branchmann-de Lange phenotype. The relationship of the mild phenotype to the full syndrome will not be understood until the pathogenetic or causal factor(s) are delineated.
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Boyd E, Schwartz CE, Schroer RJ, May MM, Shapiro SD, Arena JF, Lubs HA, Stevenson RE. Agenesis of the corpus callosum associated with MASA syndrome. Clin Dysmorphol 1993; 2:332-41. [PMID: 8305964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
MASA syndrome includes mental retardation, adducted thumbs, shuffling gait and aphasia or speech delay. MASA syndrome, X-linked hydrocephalus and X-linked spastic paraplegia have been linked to the same markers on Xq28 and perhaps represent variation in the clinical expression of the same gene or manifestations of different mutant alleles. The present family includes five males in two generations with borderline to mild mental retardation (5/5), speech delay (5/5), spastic paraplegia (5/5), adducted thumbs (2/5) and marked hydrocephalus (1/5). Of these males, four were evaluated by MRI or CT scan and all four were determined to have partial to complete agenesis of the corpus callosum (ACC). DNA studies confirm linkage to Xq28 probe St14 (DXS52) with a lod score of 2.86 and no recombination. It is not known if X-linked ACC is linked to the same Xq28 region.
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Phelan MC, Stevenson RE, Anderson EV. Recombinant chromosome 9 possibly derived from breakage and reunion of sister chromatids within a paracentric inversion loop. AMERICAN JOURNAL OF MEDICAL GENETICS 1993; 46:304-8. [PMID: 8488876 DOI: 10.1002/ajmg.1320460313] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Chromosomally unbalanced offspring resulting from the recombination of parental paracentric inversions are uncommon. We report on a 20-month-old boy with a partial duplication of 9p due to the recombination of a paternal paracentric inversion. The patient's recombinant chromosome was designated rec(9)(p13-->p24::p12-->p24::p12-->qter). The patient's father and paternal aunt have a paracentric inversion of chromosome 9:inv(9)(p13p24). Although several mechanisms have been proposed to explain the chromosome imbalance generated from paracentric inversions, none of the previously described mechanisms can account for the structure of the recombinant chromosome observed in the propositus. We propose an unusual mechanism of formation involving breakage and unequal reunion of sister chromatids within the inversion loop to explain the structure of the patient's recombinant chromosome.
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Stevenson RE, Jong SC. Application of good laboratory practice (GLP) to culture collections of microbial and cell cultures. World J Microbiol Biotechnol 1992; 8:229-35. [PMID: 24425468 DOI: 10.1007/bf01201869] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/1991] [Accepted: 12/06/1991] [Indexed: 11/26/2022]
Abstract
Although the principles and the necessity for good laboratory practice (GLP) guidelines to confirm the credibility, integrity, and quality of non-clinical laboratory studies have been known for more than a decade, culture collection activities are not subject to them. Because of recent advances in biotechnology, culture collections face increased demands not only for quality cultures but also current information. When applied in culture collections, GLP guidelines prove to be an excellent management tool as well as a cost-effective system of providing authentic and reliable microbial and cell cultures and associated data.
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Schwartz CE, May M, Huang T, Ledbetter D, Anderson G, Barker DF, Lubs HA, Arena F, Stevenson RE. MRX8: an X-linked mental retardation condition with linkage to Xq21. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 43:467-74. [PMID: 1605227 DOI: 10.1002/ajmg.1320430170] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A family in which 6 males have X-linked mental retardation has been studied with polymorphic DNA probes. The males differ from unaffected males only in impaired intellect and in smaller head size. The gene that causes mental retardation in the family appears to be located in band Xq21 on the basis of linkage with 3 markers: DXS250, DXS345 and DXS3 (theta max = 0.00; Zmax = 1.6). A multipoint lod score of 2.36 was obtain with no recombination relative to DXS326 in Xq21. This family is considered to have nonspecific X-linked mental retardation and has been given the designation MRX8.
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Bialer MG, Lawrence L, Stevenson RE, Silverberg G, Williams MK, Arena JF, Lubs HA, Schwartz CE. Allan-Herndon-Dudley syndrome: clinical and linkage studies on a second family. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 43:491-7. [PMID: 1605231 DOI: 10.1002/ajmg.1320430173] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We restudied a family with X-linked mental retardation (XLMR) originally reported in abstract form by Davis et al. [1981]. All 8 living affected males were examined. Characteristics included severe mental retardation, spastic paraplegia, dysarthria, muscle wasting, scoliosis, broad shallow pectus excavatum, long face, large ears with minor modeling anomalies, foot deformities, joint contractures, and neck drop. Stature, OFC, testicular volume, high resolution chromosome and fragile X studies, and plasma amino acids were all normal. Their manifestations closely resemble those of a large family with XLMR originally reported by Allan et al. [1944] and restudied by Stevenson et al. [1990]. This condition has been termed the Allan-Herndon-Dudley syndrome (AHDS). As AHDS has been mapped to Xq21, mapping studies were undertaken to determine if this family maps to the same location. These studies demonstrate tight linkage to Xq21, with a maximum lod score of 2.88 obtained with probe pX65H7 (DXS72). Multipoint analysis located the mutant gene quite close to pX65H7 (multipoint Z = 4.14), slightly more proximal in Xq21 than was suggested by the data from the original AHDS family. It appears likely that this family is the second reported family with AHDS.
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Graham JM, Curry CJ, Hoyme HE, Stevenson RE, Hall JG. Fellowships and career development in dysmorphology and clinical genetics. Pediatr Clin North Am 1992; 39:349-62. [PMID: 1553248 DOI: 10.1016/s0031-3955(16)38299-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This article sets forth some guiding principles for the initiation of a productive and satisfying academic career as a clinical researcher in the areas of dysmorphology, teratology, and clinical genetics. It assumes that the fellow in dysmorphology and clinical genetics is genuinely committed to the pursuit of a career in this area, but these general principles are certainly relevant to other medical specialties. It is important for pediatricians to consider careers in this area because the need for dysmorphologists and clinical geneticists will continue to increase during the foreseeable future, and the current opportunities for such training are limited.
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Boyd E, Grass FS, Parke JC, Knutson K, Stevenson RE. Duplication of distal 19q: clinical report and review. AMERICAN JOURNAL OF MEDICAL GENETICS 1992; 42:326-30. [PMID: 1536172 DOI: 10.1002/ajmg.1320420314] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report on a 20-month-old boy with duplication of the distal part of 19q. His karyotype is 46,XY, -22, + der(22),t(19;22)(q13.3;p11.2)mat. The propositus has multiple minor anomalies, congenital heart defects, seizures, profound psychomotor retardation, and growth impairment. These characteristics are similar to those in the other 10 reported cases of distal 19q duplication and help delineate the phenotype. A review of the literature is presented.
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