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Lawrence M Silverman

Publications and source records attributed to Lawrence M Silverman.

9 recordsLinked to original sources
PubMed2006

Molecular diagnostics: a historical perspective.

The rapid growth in molecular diagnostic testing, which has averaged between 10% and 20% per year for the past 5 years, is largely attributable to both breakthroughs in our basic understanding (i.e., the Human Genome Project) and in applied technology. In the past decade, molecular applications have moved from labor-intensive and manual to rapid and automated due to improvements in sample extraction, target amplification, and sensitive and specific detection schema. This review describes some of the more significant technological milestones of the past 10 years and, when tied to basic and applied research, how these have led to important clinical applications. The next decade promises even more exciting technologies and applications for the field of molecular laboratory medicine.

Clinical Laboratory Techniques↗
PubMed2006

Acceptance of fragile X premutation genetic screening in women with ovarian dysfunction.

OBJECTIVE: The purpose of this study was to assess patient perception of fragile X premutation genetic testing (FRAX). STUDY DESIGN: This was a cross-sectional survey of women with elevated follicle stimulating hormone levels with (premature ovarian failure or early menopause [POF/EM], n = 20) or without (diminished ovarian reserve [DOR], n = 20) amenorrhea. Seventy-five percent participated. RESULTS: Seventy-five percent of the DOR group and 43% of the POF/EM group desired FRAX testing. Eighty-three percent wanted to assist the scientific knowledge of FRAX, even if they did not want to know their own results. POF/EM women were more concerned than DOR women about paying out-of-pocket (P = .001) and maintaining confidentiality insurance-wise (P = .07). Primary motivations for women who wanted testing were the desire to know if they have FRAX, and wanting to determine if FRAX is the cause of their ovarian dysfunction. The primary decision factor for those declining testing was unwillingness to pay out-of-pocket (75%). CONCLUSION: Women with ovarian dysfunction are interested in FRAX testing. Cost, confidentiality, and the implications for relatives are their key concerns.

Adult↗
PubMed2005

Developing a sustainable process to provide quality control materials for genetic testing.

PURPOSE: To provide a summary of the outcomes of two working conferences organized by the Centers for Disease Control and Prevention (CDC), to develop recommendations for practical, sustainable mechanisms to make quality control (QC) materials available to the genetic testing community. METHODS: Participants were selected to include experts in genetic testing and molecular diagnostics from professional organizations, government agencies, industry, laboratories, academic institutions, cell repositories, and proficiency testing (PT)/external Quality Assessment (EQA) programs. Current efforts to develop QC materials for genetic tests were reviewed; key issues and areas of need were identified; and workgroups were formed to address each area of need and to formulate recommendations and next steps. RESULTS: Recommendations were developed toward establishing a sustainable process to improve the availability of appropriate QC materials for genetic testing, with an emphasis on molecular genetic testing as an initial step. CONCLUSIONS: Improving the availability of appropriate QC materials is of critical importance for assuring the quality of genetic testing, enhancing performance evaluation and PT/EQA programs, and facilitating new test development. To meet the needs of the rapidly expanding capacity of genetic testing in clinical and public health settings, a comprehensive, coordinated program should be developed. A Genetic Testing Quality Control Materials Program has therefore been established by CDC in March 2005 to serve these needs.

Centers for Disease Control and Prevention, U.S.↗
PubMed2003

Association between hemochromatosis (HFE) gene mutation carrier status and the risk of colon cancer.

BACKGROUND: Iron is a pro-oxidant that may promote carcinogenesis. Mutations in the hemochromatosis (HFE) gene are associated with increased total body iron stores in some individuals. We assessed the risk of colon cancer among individuals with and without HFE gene mutations. METHODS: We performed a population-based, case-control study in North Carolina. Case patients with colon cancer and control subjects provided information on multiple environmental exposures, including total iron intake and nonsteroidal anti-inflammatory drug (NSAID) use. They also provided a venous blood sample, from which DNA was extracted, amplified, and subjected to diagnostic restriction enzyme mapping to detect two major HFE gene mutations, C282Y and H63D. Data were analyzed with Fisher's exact test and logistic regression. All statistical tests were two-sided. RESULTS: Thirteen hundred and eight subjects participated (475 case patients, 833 control subjects). The allele frequencies of the H63D and C282Y mutations were greater among case patients (0.11 and 0.046, respectively) than among control subjects (0.09 and 0.044, respectively; P =.14 and P =.85, respectively). When we controlled for age, race, sex, red meat consumption, NSAID use, and total iron intake, subjects with any HFE gene mutation were more likely to have colon cancer than subjects with no HFE gene mutations (adjusted odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.07 to 1.87). The magnitude of the effect was similar for both the H63D (adjusted OR = 1.44, 95% CI = 1.04 to 1.98) and C282Y mutations (adjusted OR = 1.39, 95% CI = 0.88 to 2.19). The risk of colon cancer associated with an HFE gene mutation was similar for those who did and did not have a family history of colon cancer. Among those with HFE mutations, cancer risk increased with increasing age and total iron intake. CONCLUSIONS: HFE gene mutations are associated with an increased risk of colon cancer. Cancer risk is greatest in mutation carriers who are older or consume high quantities of iron.

Age Factors↗
PubMed2002

A novel mutation in exon 5 of the ALAS2 gene results in X-linked sideroblastic anemia.

BACKGROUND: Mutations in the erythroid-specific 5-aminolevulinate-synthase gene (ALAS2) have been identified in many cases of X-linked sideroblastic anemia (XLSA). METHODS: A polymerase chain reaction-mediated restriction fragment length polymorphism (RFLP) assay was used. RESULTS: A G527T point mutation was identified. This resulted in a substitution of tyrosine for asparagine at residue 159 (D159Y). This mutation was also identified in the mother of the two probands. Mutations in all three individuals were confirmed by DNA sequencing analysis. CONCLUSIONS: We identified a missense mutation in exon 5 of the ALAS2 gene in two brothers of a consanguineous marriage, who were clinically pyridoxine-responsive.

5-Aminolevulinate Synthetase↗
PubMedDate not supplied

The I148T CFTR allele occurs on multiple haplotypes: a complex allele is associated with cystic fibrosis.

PURPOSE: To determine whether intragenic changes modulate the cystic fibrosis (CF) phenotype in individuals who are positive for the I148T allele. METHODS: The genes from individuals who carried at least one copy of the I148T allele were analyzed for additional changes that may be acting as genetic modifiers. RESULTS: Seven of eight individuals with a known or suspected diagnosis of CF who carried I148T in combination with a severe CF mutation also carried 3199del6. Eight apparently healthy adult individuals who were compound heterozygous for I148T and a severe CF mutation or homozygous for I148T did not carry the deletion ( = 0.0014). The I148T allele occurs on at least three haplotypes: an IVS-8 9T background, a 7T background, or a 9T + 3199del6 background. The 3199del6 allele was not identified in 386 non-CF chromosomes. CONCLUSIONS: It is concluded that I148T occurs on at least three haplotypes and the complex allele I148T + 9T + 3199del6 is associated with a classic CF phenotype.

Adolescent↗
PubMedDate not supplied

CFTR mutation distribution among U.S. Hispanic and African American individuals: evaluation in cystic fibrosis patient and carrier screening populations.

PURPOSE: We reviewed CFTR mutation distribution among Hispanic and African American individuals referred for CF carrier screening and compared mutation frequencies to those derived from CF patient samples. METHODS: Results from CFTR mutation analyses received from January 2001 through September 2003, were analyzed for four populations: Hispanic individuals with a CF diagnosis (n = 159) or carrier screening indication (n = 15,333) and African American individuals with a CF diagnosis (n = 108) or carrier screening indication (n = 8,973). All samples were tested for the same 87 mutation panel. RESULTS: In the Hispanic population, 42 mutations were identified: 30 in the patient population (77.5% detection rate) and 33 among carrier screening referrals. Five mutations not included in the ACMG/ACOG carrier screening panel (3876delA, W1089X, R1066C, S549N, 1949del84) accounted for 7.55% detection in patients and 5.58% among carriers. Among African American referrals, 33 different mutations were identified: 21 in the patient population (74.4% detection) and 23 in the carrier screening population. Together, A559T and 711+5G>A were observed at a detection rate of 3.71% in CF patients and 6.38% in carriers. The mutation distribution seen in both the carrier screening populations reflected an increased frequency of mutations with variable expression such as D1152H, R117H, and L206W. CONCLUSIONS: A detailed analysis of CFTR mutation distribution in the Hispanic and African American patient and carrier screening populations demonstrates that a diverse group of mutations is most appropriate for diagnostic and carrier screening in these populations. To best serve the increasingly diverse U.S. population, ethnic-specific mutations should be included in mutation panels.

Adolescent↗