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Biomedical subjects

C M Eng

Publications and source records attributed to C M Eng.

At least 19 recordsLinked to original sources

Safety and efficacy of recombinant human alpha-galactosidase A replacement therapy in Fabry's disease.

BACKGROUND: Fabry's disease, lysosomal alpha-galactosidase A deficiency, results from the progressive accumulation of globotriaosylceramide and related glycosphingolipids. Affected patients have microvascular disease of the kidneys, heart, and brain. METHODS: We evaluated the safety and effectiveness of recombinant alpha-galactosidase A in a multicenter, randomized, placebo-controlled, double-blind study of 58 patients who were treated every 2 weeks for 20 weeks. Thereafter, all patients received recombinant alpha-galactosidase A in an open-label extension study. The primary efficacy end point was the percentage of patients in whom renal microvascular endothelial deposits of globotriaosylceramide were cleared (reduced to normal or near-normal levels). We also evaluated the histologic clearance of microvascular endothelial deposits of globotriaosylceramide in the endomyocardium and skin, as well as changes in the level of pain and the quality of life. RESULTS: In the double-blind study, 20 of the 29 patients in the recombinant alpha-galactosidase A group (69 percent) had no microvascular endothelial deposits of globotriaosylceramide after 20 weeks, as compared with none of the 29 patients in the placebo group (P<0.001). Patients in the recombinant alpha-galactosidase A group also had decreased microvascular endothelial deposits of globotriaosylceramide in the skin (P<0.001) and heart (P<0.001). Plasma levels of globotriaosylceramide were directly correlated with clearance of the microvascular deposits. After six months of open-label therapy, all patients in the former placebo group and 98 percent of patients in the former recombinant alpha-galactosidase A group who had biopsies had clearance of microvascular endothelial deposits of globotriaosylceramide. The incidence of most treatment-related adverse events was similar in the two groups, with the exception of mild-to-moderate infusion reactions (i.e., rigors and fever), which were more common in the recombinant alpha-galactosidase A group. IgG seroconversion occurred in 88 percent of patients who received recombinant alpha-galactosidase A. CONCLUSIONS: Recombinant alpha-galactosidase A replacement therapy cleared microvascular endothelial deposits of globotriaosylceramide from the kidneys, heart, and skin in patients with Fabry's disease, reversing the pathogenesis of the chief clinical manifestations of this disease.

Adolescent↗

A phase 1/2 clinical trial of enzyme replacement in fabry disease: pharmacokinetic, substrate clearance, and safety studies.

Fabry disease results from deficient alpha-galactosidase A (alpha-Gal A) activity and the pathologic accumulation of the globotriaosylceramide (GL-3) and related glycosphingolipids, primarily in vascular endothelial lysosomes. Treatment is currently palliative, and affected patients generally die in their 40s or 50s. Preclinical studies of recombinant human alpha-Gal A (r-halphaGalA) infusions in knockout mice demonstrated reduction of GL-3 in tissues and plasma, providing rationale for a phase 1/2 clinical trial. Here, we report a single-center, open-label, dose-ranging study of r-halphaGalA treatment in 15 patients, each of whom received five infusions at one of five dose regimens. Intravenously administered r-halphaGalA was cleared from the circulation in a dose-dependent manner, via both saturable and non-saturable pathways. Rapid and marked reductions in plasma and tissue GL-3 were observed biochemically, histologically, and/or ultrastructurally. Clearance of plasma GL-3 was dose-dependent. In patients with pre- and posttreatment biopsies, mean GL-3 content decreased 84% in liver (n=13), was markedly reduced in kidney in four of five patients, and after five doses was modestly lowered in the endomyocardium of four of seven patients. GL-3 deposits were cleared to near normal or were markedly reduced in the vascular endothelium of liver, skin, heart, and kidney, on the basis of light- and electron-microscopic evaluation. In addition, patients reported less pain, increased ability to sweat, and improved quality-of-life measures. Infusions were well tolerated; four patients experienced mild-to-moderate reactions, suggestive of hypersensitivity, that were managed conservatively. Of 15 patients, 8 (53%) developed IgG antibodies to r-halphaGalA; however, the antibodies were not neutralizing, as indicated by unchanged pharmacokinetic values for infusions 1 and 5. This study provides the basis for a phase 3 trial of enzyme-replacement therapy for Fabry disease.

Adolescent↗

Nonradioactive detection of the common Connexin 26 167delT and 35delG mutations and frequencies among Ashkenazi Jews.

Mutations in the gap junction beta2 (GJB2) gene, Connexin 26 (Cx26), cause nonsyndromic sensorineural recessive deafness (NSRD). Two frameshift mutations, 167delT and 35delG, are the most frequent Cx26 lesions causing NSRD. The 35delG mutation is panethnic, while the 167delT lesion occurs almost exclusively in the Ashkenazi Jewish population at a carrier frequency of 2 to 4%. To facilitate carrier detection, a simple nonradioactive allele-specific oligonucleotide (ASO) hybridization assay was developed for the 167delT and 35delG mutations. Screening of 1012 anonymous Ashkenazi Jewish individuals from the New York Metropolitan area revealed carrier frequencies for 167delT and 35delG of 3.96% (95% CI: 2.75-5.15%) and 0.69% (95% CI: 0.18-1.20%), respectively. This sensitive, specific, and relatively inexpensive method can reliably identify affected newborns and patients with NSRD as well as facilitate carrier screening for Connexin 26 deafness in the Ashkenazi Jewish community.

Connexin 26↗

Fabry disease: twenty novel alpha-galactosidase A mutations causing the classical phenotype.

Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from the deficient activity of the lysosomal exoglycohydrolase, alpha-galactosidase A (EC 3.2.1.22; alpha-Gal A). The nature of the molecular lesions in the alpha-Gal A gene in 40 unrelated families with the classical phenotype (absent alpha-Gal A activity) was determined in order to provide precise heterozygote detection and prenatal diagnosis, and to explore possible genotype/phenotype correlations. Genomic DNA was isolated from unrelated affected males, and the entire alpha-Gal A coding region and flanking intronic sequences were analyzed by polymerase chain reaction (PCR) amplification and automated sequencing. Twenty new mutations were identified: M51K, D92N, D136H, F169S, C172F, L191Q, S247P, Q250X, P259R, G261D, T282N, R301P, W349X, T410K, 124delAT, 842delTAA, 1033delTC, 82insG, 893insG, and 903insG. In the remaining 20 unrelated Fabry families, 17 previously reported mutations were detected. These studies further define the heterogeneity of mutations in the alpha-Gal A gene causing the classic Fabry disease phenotype, and permit precise heterozygote detection and prenatal diagnosis.

DNA Mutational Analysis↗

Experiences in molecular-based prenatal screening for Ashkenazi Jewish genetic diseases.

Multiple-option prenatal carrier testing in the Ashkenazi Jewish community for three and now eight disorders has been readily accepted in this prenatal, health-oriented and knowledgeable population. Counseling of screenees concerning the nature (severity, treatability, etc.), inheritance, and frequencies of each disorder was essential for informed test choices and future reproductive decision making. The value of couple testing for a group of disorders when 1 in about 6 would be found to be a carrier of at least one disease was emphasized. These studies identified issues of education, confidentiality, posttest anxiety, and self-esteem that must be continuously addressed in the Ashkenazi population. However, an important value of these studies is that they provide a framework for the development of mass carrier screening programs in the general population or in specific segments of the population with similar demographic characteristics and in more diverse prenatal populations.

Genes, Recessive↗

The lifetime risks of breast cancer in Ashkenazi Jewish carriers of BRCA1 and BRCA2 mutations.

Several studies using families with multiple occurrences of breast cancer have provided evidence for a very high lifetime penetrance in carriers of BRCA1 or BRCA2 mutations. However, there are reasons to suspect that the estimates of penetrance from studies of cancer families may be inflated. Access to the genotypes of incident cases of breast cancer in three hospitals and from a large series of unaffected survey participants provided the basis for direct estimation of the age-specific relative risks attributable to these mutations, and the resulting lifetime penetrance, without any reference to familial aggregation of cancer. Cases were identified from incident series of Jewish patients treated for primary breast cancer at the three hospitals. Control data were obtained from the large series of Jewish women recruited in the Washington, D.C., area by investigators at the National Cancer Institute and limited to 3434 women with no previous history of breast or ovarian cancer. All subjects were genotyped for the three mutations that are relatively common in Ashkenazi Jews, namely 185delAG and 5382 insC in BRCA1 and 6174delT in BRCA2. For BRCA1, the relative risks of breast cancer were estimated to be 21.6 in women under 40 years of age, 9.6 in women 40-49 years of age, and 7.6 in women > or = 50 years of age. On the basis of these estimates, the penetrance of breast cancer at age 70 among BRCA1 mutation carriers is estimated to be 46% (95% confidence, 31%-80%) rising to 59% (95% confidence, 40%-93%) at age 80. For BRCA2, the relative risks in the same three age categories were estimated to be 3.3, 3.3, and 4.6, respectively, resulting in a penetrance at age 70 of 26% (95% confidence, 14%-50%) rising to 38% (95% confidence, 20%-68%) at age 80. The lifetime risk of breast cancer in Jewish women who are mutation carriers estimated via this approach is substantially lower than the reported lifetime risks estimated using multiple-case families. The risks appear to be different for carriers of BRCA1 and BRCA2 mutations.

Adult↗

Fabry disease: twenty-two novel mutations in the alpha-galactosidase A gene and genotype/phenotype correlations in severely and mildly affected hemizygotes and heterozygotes.

BACKGROUND: Fabry disease, an inborn error of glycosphingolipid catabolism, results from mutations in the X-chromosomal gene encoding the lysosomal exoglycosidase, alpha-galactosidase A (alpha-Gal A; EC 3.2.1.22). The nature of the molecular lesions in the alpha-Gal A gene in 36 unrelated families was determined in order to provide precise heterozygote detection, prenatal diagnosis, and to define genotype/phenotype correlations. METHODS: Genomic DNA was isolated from affected males and/or carrier females from 36 unrelated families with Fabry disease. The entire alpha-Gal A coding region and flanking intronic sequences were analyzed by PCR amplification and solid-phase or cycle sequencing. Markers closely linked to the alpha-Gal A gene were analyzed to determine if probands with the same mutations were related. RESULTS: Twenty-two novel mutations were identified including 10 missense (P40L, W95S, S148N, C172R, M187V, N224S, W226R, A230T, D266H, N320Y), three nonsense (Y134X, C142X, W204X in two families), three splice-site defects (IVS2(+1), IVS3(+1), IVS4(+1)) and six small deletions or insertions (26delA in two families, 672ins37, 774delAC, 833insA, 1139delC, 1188insT). Of the remaining 12 families (33.3%), each had a previously identified mutation, eight of which occurred at CpG dinucleotides including R112C (two families), R112H, R227Q, R227X (three families), and R301Q. Haplotype analysis of the mutant alleles that occurred in two or three presumably unrelated families revealed that the families with the rare novel alleles (W204X and 26delA) were probably related, whereas those with mutations involving CpG dinucleotides (R112C and R227X) were not, the latter being consistent with their origins as independent mutational events. Genotype/phenotype correlations revealed that certain mutations previously found in mild variant patients also were found in classic patients. In addition, the genotypes and spectrum of phenotypic severity were determined in five heterozygotes with no family history. CONCLUSIONS: These results illustrate the molecular heterogeneity of the lesions causing Fabry disease and emphasize the fact that CpG dinucleotides constitute important hot spots for mutation in the alpha-Gal A gene. These studies also permit precise heterozygote detection and prenatal diagnosis in these families, and delineate phenotype-genotype correlations in this disease.

Amino Acid Sequence↗

Fabry disease: comparison of enzymatic, linkage, and mutation analysis for carrier detection in a family with a novel mutation (30delG).

Fabry disease (FD) is an X-linked recessive disorder caused by the deficient activity of the lysosomal enzyme alpha-galactosidase A (alpha-Gal A). Affected males are reliably diagnosed by demonstration of deficient alpha-Gal A activity in plasma or leukocytes. However, identification of female carriers is problematic due to Lyonization, requiring mutation identification and/or linkage studies for accurate carrier detection. Here, we describe a large Brazilian kindred with Fabry disease that permitted comparison of biochemical and molecular diagnostic techniques. Initially, the plasma alpha-Gal A activities were determined in at-risk affected males and potential female carriers; affected males were readily diagnosed, while the females had variable results. To detect carrier females, haplotype analysis using 10 polymorphic markers adjacent to the gene was performed. Subsequently, solid-phase direct sequencing of the alpha-Gal A gene demonstrated a novel single base deletion in exon 1 (30delG). Discrepancies were observed between the enzymatic and molecular diagnoses in two at-risk females. These findings emphasize the need for precise heterozygote diagnosis by mutation and/or haplotype analyses in all families with Fabry disease.

Base Sequence↗

Molecular exclusion of haemoglobin SD disease by prenatal diagnosis.

The most common Hb D variant, Haemoglobin D (Hb D) Los Angeles is caused by a glutamic acid to glutamine substitution at codon 121 of the beta globin gene. Although asymptomatic in the heterozygous form, inheritance together with an Hb S allele can result in a severe disease similar to sickle-cell anaemia that is referred to as Hb SD disease. Prenatal diagnosis for Hb SD disease was requested by an at-risk couple of Irish/English descent. Prenatal diagnosis was performed on DNA isolated from chorionic villi at 12 weeks' gestation using dot blot and allele-specific oligonucleotide hybridization for the HbS mutation, and two independent approaches, restriction fragment analysis and ARMS (amplification refractory mutation system) for the detection of the Hb D Los Angeles mutation. The fetus was found to be heterozygous for the HbS mutation, but did not inherit the HbD mutation. Thus, a reliable and rapid prenatal diagnosis for the Hb SD disease can be achieved by molecular diagnosis.

Alleles↗

Twenty novel mutations in the alpha-galactosidase A gene causing Fabry disease.

BACKGROUND: Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from the deficient activity of the lysosomal exoglycohydrolase alpha-galactosidase A (EC 3.2.1.22; alpha-Gal A). The nature of the molecular lesions in the alpha-Gal A gene in 30 unrelated families was determined to provide precise heterozygote detection, prenatal diagnosis, and define genotype-phenotype correlations. MATERIALS AND METHODS: Genomic DNA was isolated from affected males and/or carrier females from 30 unrelated families with Fabry disease. The entire alpha-Gal A coding region and flanking intronic sequences were analyzed by PCR amplification and automated sequencing. RESULTS: Twenty new mutations were identified, each in a single family: C142R, G183D, S235C, W236L, D244H, P259L, M267I, I289F, Q321E, C378Y, C52X, W277X, IVS4(+4), IVS6(+2), IVS6(-1), 35del13, 256del1, 892ins1, 1176del4, and 1188del1. In the remaining 10 unrelated Fabry families, 9 previously reported mutations were detected: M42V, R112C, S148R, D165V, N215S (in 2 families), Q99X, C142X, R227X, and 1072del3. Haplotype analysis using markers closely flanking the alpha-Gal A gene indicated that the two patients with the N215S lesion were unrelated. The IVS4(+4) mutation was a rare intronic splice site mutation that causes Fabry disease. CONCLUSIONS: These studies further define the heterogeneity of mutations in the alpha-Gal A gene causing Fabry disease, permit precise heterozygote detection and prenatal diagnosis, and help delineate phenotype-genotype correlations in this disease. </AB

Alternative Splicing↗

Frequency and carrier risk associated with common BRCA1 and BRCA2 mutations in Ashkenazi Jewish breast cancer patients.

Based on breast cancer families with multiple and/or early-onset cases, estimates of the lifetime risk of breast cancer in carriers of BRCA1 or BRCA2 mutations may be as high as 85%. The risk for individuals not selected for family history or other risk factors is uncertain. We determined the frequency of the common BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) mutations in a series of 268 anonymous Ashkenazi Jewish women with breast cancer, regardless of family history or age at onset. DNA was analyzed for the three mutations by allele-specific oligonucleotide hybridization. Eight patients (3.0%, 95% confidence interval [CI] 1.5%-5.8%) were heterozygous for the 185delAG mutation, two (0.75%, 95% CI 0.20-2.7) for the 5382insC mutation, and eight (3.0%, 95% CI 1.5-5.8) for the 6174delT mutation. The lifetime risk for breast cancer in Ashkenazi Jewish carriers of the BRCA1 185delAG or BRCA2 6174delT mutations was calculated to be 36%, approximately three times the overall risk for the general population (relative risk 2.9, 95% CI 1.5-5.8). For the 5382insC mutation, because of the low number of carriers found, further studies are necessary. The results differ markedly from previous estimates based on high-risk breast cancer families and are consistent with lower estimates derived from a recent population-based study in the Baltimore area. Thus, presymptomatic screening and counseling for these common mutations in Ashkenazi Jewish women not selected for family history of breast cancer should be reconsidered until the risk associated with these mutations is firmly established, especially since early diagnostic and preventive-treatment modalities are limited.

Adult↗

Prenatal genetic carrier testing using triple disease screening.

CONTEXT: Rapid progress in gene discovery has dramatically increased diagnostic capabilities for carrier screening and prenatal testing for genetic diseases. However, simultaneous prenatal carrier screening for prevalent genetic disease has not been evaluated, and patient acceptance and attitudes toward this testing strategy remain undefined. OBJECTIVE: To evaluate an educational, counseling, and carrier testing program for 3 genetic disorders: Tay-Sachs disease (TSD), type 1 Gaucher disease (GD), and cystic fibrosis (CF) that differ in detectability, severity, and availability of therapy. DESIGN: Potential participants received education and genetic counseling, gave informed consent, chose screening tests, and completed pre-education and posteducation questionnaires that assessed knowledge, attitudes toward genetic testing, and disease testing preferences. SETTING: Medical genetics referral center. PATIENTS: Volunteer sample of 2824 Ashkenazi Jewish individuals enrolled as couples who were referred for TSD testing. INTERVENTION: Genetic counseling, education, and if chosen, genetic testing for any or all 3 disorders. MAIN OUTCOME MEASURE: Acceptance of screening for each of the 3 disorders. Secondary outcomes include attitudes toward genetic testing and reproductive considerations. RESULTS: Of the 2824 individuals tested for TSD, 97% and 95% also chose testing for CF and GD, respectively. The frequency of detected carriers was 1:21 for TSD, 1 :25 for CF, and 1:18 for GD. Twenty-one carriercoupleswere identified, counseled, and all postconception couples opted for prenatal diagnosis. Pre-education and posteducation questionnaires revealed that patients initially knew little about the diseases, but acquired disease information and increased knowledge of genetic concepts. Education and genetic counseling increased understanding and retention of genetic concepts and disease-related information, and minimized test-related anxiety. Although individuals sought screening for all 3 diseases, reproductive attitudes and decisions varied directly with disease severity and treatability. CONCLUSIONS: These findings emphasize the importance of genetic counseling for prenatal carrier testing and may improve understanding, acceptance, and informed decision making for prenatal carrier screening for multiple genetic diseases.

Adult↗

Fabry disease: molecular carrier detection and prenatal diagnosis by analysis of closely linked polymorphisms at Xq22.1.

Fabry disease is an X-linked recessive inborn error of glycosphingolipid catabolism that results from the deficient activity of the lysosomal enzyme alpha-galactosidase A (alpha-Gal A). A rapid, reliable, and universal linkage method was developed for molecular carrier detection and prenatal diagnosis. By determining the informativeness and phase of amplifiable intragenic RFLPs (NcoI and SacI), flanking RFLPs (DXS94 and DXS17), and flanking microsatellite polymorphisms at Xq22.1 (DXS458, DXS454, DXS7424, DXS178, and DXS101), accurate carrier detection, and/or prenatal diagnosis was accomplished in three prototypic, unrelated Fabry families. All linkage diagnoses were confirmed by identification and analysis of the specific alpha-Gal A lesion in each family. Thus, molecular carrier detection and prenatal diagnoses can be performed rapidly and reliably by linkage analysis with intragenic and closely-linked polymorphisms at Xq22.1 in Fabry families whose specific alpha-Gal A lesions have not been determined.

Amino Acid Sequence↗

Pulmonary involvement in Fabry disease.

Fabry disease is an X-linked inborn error of metabolism resulting from deficient activity of alpha-galactosidase A. Although several case reports have suggested an association between Fabry disease and airway obstruction, this has not been investigated in a large series of patients. We studied 25 unselected, consecutive, enzymatically diagnosed men referred to a General Clinical Research Center for evaluation. Thirty-six percent complained of dyspnea, and 24% had cough and/or wheezing. Symptoms were similar in smokers and nonsmokers. Nine (36%) had airway obstruction on spirometry; this finding was associated with age > or = 26 yr (p < 0.05) and dyspnea or wheezing (p < 0.005), but only weakly with smoking (p = 0.062). Five of eight patients responded to bronchodilators, but all 10 methacholine challenges were negative. Chest radiographs revealed normal lung fields in 24 patients and streaky bibasilar densities in one. No pulmonary uptake occurred on 67Ga citrate scans (18 patients) and 111In-tagged leukocyte scans (16 patients). Specific alpha-galactosidase A mutations were identified in 17 patients; all three patients with frameshift mutations and both subjects with the D264V missense mutation had obstructive impairment. We conclude that airway obstruction commonly occurs in patients with Fabry disease regardless of smoking history, and it increases with age. The presence of obstruction may be associated with certain mutations and most likely results from fixed narrowing of the airways by accumulated glycosphingolipid.

Adolescent↗

Fabry disease: thirty-five mutations in the alpha-galactosidase A gene in patients with classic and variant phenotypes.

BACKGROUND: Fabry disease, an X-linked inborn error of glycosphingolipid catabolism, results from mutations in the alpha-galactosidase A (alpha-Gal A) gene located at Xq22.1. To determine the nature and frequency of the molecular lesions causing the classical and milder variant Fabry phenotypes and for precise carrier detection, the alpha-Gal A lesions in 42 unrelated Fabry hemizygotes were determined. MATERIALS AND METHODS: Genomic DNA was isolated from affected probands and their family members. The seven alpha-galactosidase A exons and flanking intronic sequences were PCR amplified and the nucleotide sequence was determined by solid-phase direct sequencing. RESULTS: Two patients with the mild cardiac phenotype had missense mutations, I9IT and F113L, respectively. In 38 classically affected patients, 33 new mutations were identified including 20 missense (MIT, A31V, H46R, Y86C, L89P, D92Y, C94Y, A97V, R100T, Y134S, G138R, A143T, S148R, G163V, D170V, C202Y, Y216D, N263S, W287C, and N298S), two nonsense (Q386X, W399X), one splice site mutation (IVS4 + 2T-->C), and eight small exonic insertions or deletions (304del1, 613del9, 777del1, 1057del2, 1074del2, 1077del1, 1212del3, and 1094ins1), which identified exon 7 as a region prone to gene rearrangements. In addition, two unique complex rearrangements consisting of contiguous small insertions and deletions were found in exons 1 and 2 causing L45R/H46S and L120X, respectively. CONCLUSIONS: These studies further define the heterogeneity of mutations causing Fabry disease, permit precise carrier identification and prenatal diagnosis in these families, and facilitate the identification of candidates for enzyme replacement therapy.

Chromosome Mapping↗

HLA-DQA1 and polymarker allele frequencies in two New York City Jewish populations.

Allele and genotype frequencies were determined for the HLA-DQA1 and Amplitype Polymarker loci (low density lipoprotein receptor (LDLR), glycophorin A (GYPA), hemoglobin G gammaglobin (HBGG), D7S8, and group-specific component (Gc)) in Hasidic and non-Hasidic Ashkenazi New York City Jewish subpopulations. For all loci tested, except HBGG, the 2 subpopulations meet the assumption of Hardy-Weinberg equilibrium. Comparison of various allele and genotype frequencies for the Hasidic and the non-Hasidic groups showed no significant differences. Comparison of the various allele frequencies in the two subpopulations to another Caucasian group revealed significant differences at the HLA-DQA1 and D7S8 loci in the Hasidic group. These frequency data can be used for comparison to other populations and for frequency estimates in DNA profiling.

Blood Grouping and Crossmatching↗

Molecular prenatal diagnosis of glycogen storage disease type Ia.

Glycogen storage disease type Ia (GSD Ia, von Gierke disease) is an autosomal recessive inborn error of metabolism caused by the deficiency of D-glucose-6-phosphatase (G6Pase). Since this enzyme is expressed primarily in hepatocytes, couples at risk for GSD type Ia relied on fetal liver biopsy for prenatal diagnosis. The recent isolation of the G6Pase gene and identification of several disease-causing mutations have permitted molecular prenatal diagnosis using amniocytes or chorionic villi. Chorionic villus sampling (CVS) was performed in an Ashkenazi Jewish family in whom a previous child was homoallelic and both parents were heterozygous for the R83C mutation. Molecular analysis revealed that the fetus was not affected. The prenatal diagnosis was confirmed postnatally by biochemical and molecular studies. Thus, the molecular prenatal diagnosis of GSD type Ia can be safely and accurately made in the first trimester.

Base Sequence↗