12 research outputs found
Application of the New Classification on Patients with a Disorder of Sex Development in Indonesia
Disorder of sex development (DSD) patients in Indonesia most often do not receive a proper diagnostic evaluation and treatment. This study intended to categorize 88 Indonesian patients in accordance with the new consensus DSD algorithm. Diagnostic evaluation including clinical, hormonal, genetic, imaging, surgical, and histological parameters was performed. Fifty-three patients were raised as males, and 34 as females. Of 22 patients with 46, XX DSD, 15 had congenital adrenal hyperplasia, while in one patient, an ovarian Leydig cell tumor was found. In all 58 46, XY DSD patients, 29 were suspected of a disorder of androgen action (12 with an androgen receptor mutation), and in 9, gonadal dysgenesis was found and, in 20, severe hypospadias e.c.i. Implementation of the current consensus statement in a resource-poor environment is very difficult. The aim of the diagnostic workup in developing countries should be to end up with an evidence-based diagnosis. This is essential to improve treatment and thereby to improve the patients' quality of life
High-Throughput Screening for Modulators of CFTR Activity Based on Genetically Engineered Cystic Fibrosis Disease-Specific iPSCs
Organotypic culture systems from disease-specific induced pluripotent stem cells (iPSCs) exhibit obvious advantages compared with
immortalized cell lines and primary cell cultures, but implementation of iPSC-based high-throughput (HT) assays is still technically challenging. Here, we demonstrate the development and conduction of an organotypic HT Cl/I exchange assay using cystic fibrosis (CF)
disease-specific iPSCs. The introduction of a halide-sensitive YFP variant enabled automated quantitative measurement of Cystic Fibrosis
Transmembrane Conductance Regulator (CFTR) function in iPSC-derived intestinal epithelia. CFTR function was partially rescued by
treatment with VX-770 and VX-809, and seamless gene correction of the p.Phe508del mutation resulted in full restoration of CFTR function. The identification of a series of validated primary hits that improve the function of p.Phe508del CFTR from a library of 42,500
chemical compounds demonstrates that the advantages of complex iPSC-derived culture systems for disease modeling can also be utilized
for drug screening in a true HT format
Mucopolysaccharidosis type IIIB may predominantly present with an attenuated clinical phenotype
Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage disorder caused by deficiency of the enzyme N-acetyl-α-D-glucosaminidase (NAGLU). Information on the natural course of MPS IIIB is scarce but much needed in view of emerging therapies. To improve knowledge on the natural course, data on all 52 MPS IIIB patients ever identified by enzymatic studies in the Netherlands were gathered. Clinical data on 44 patients could be retrieved. Only a small number (n = 9; 21%) presented with a classical MPS III phenotype; all other patients showed a much more attenuated course of the disease characterized by a significantly slower regression of intellectual and motor abilities. The majority of patients lived well into adulthood. First signs of the disease, usually mild developmental delay, were observed at a median age of 4 years. Subsequently, patients showed a slowing and eventually a stagnation of development. Patients with the attenuated phenotype had a stable intellectual disability for many years. Molecular analysis was performed in 24 index patients. The missense changes p.R643C, p.S612G, p.E634K, and p.L497V were exclusively found in patients with the attenuated phenotype. MPS IIIB comprises a remarkably wide spectrum of disease severity, and an unselected cohort including all Dutch patients showed a large proportion (79%) with an attenuated phenotype. MPS IIIB must be considered in patients with a developmental delay, even in the absence of a progressive decline in intellectual abilities. A key feature, necessitating metabolic studies, is the coexistence of behavioral problems
Association of rare MSH6 variants with familial breast cancer
Germline mutations in the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 predispose to Lynch syndrome (also known as hereditary non-polyposis colorectal cancer). Recently, we have shown that the CHEK2 1100delC mutation also is associated with Lynch syndrome/Lynch syndrome-associated families albeit in a polygenic setting. Two of the ten CHEK2 1100delC positive Lynch syndrome families additionally carried a pathogenic MLH1 or MSH6 mutation, suggesting that mutations in mismatch repair genes may be involved in CHEK2 1100delC-associated cancer phenotypes. A phenotype of importance is hereditary breast and colorectal cancer (HBCC), with the CHEK2 1100delC mutation present in almost one-fifth of the families-again in a polygenic setting. In order to evaluate the involvement of MSH6 in polygenic CHEK2 cancer susceptibility, we, here, have analyzed the entire MSH6 coding sequence for genetic alterations in 68 HBCC breast cancer families. Rare MSH6 variants, with population frequencies below 1%, were identified in 11.8% of HBCC breast cancer families, whereas the same variants were identified in only 1.5% of population controls, suggesting that rare MSH6 variants are associated with HBCC breast cancer (P <or = 0.00001). However, screening of the entire MSH6 coding sequence in 68 non-HBCC breast cancer families showed a similar association (8.8 vs. approximately 1.4% in controls, P <or = 0.001), suggesting that rare MSH6 variants are not confined to HBCC breast cancer. Together, our data suggest that rare MSH6 variants may predispose to familial breast cancer. However, none of the rare MSH6 variants are obviously pathogenic, suggesting that a more subtle disease mechanism may operate in breast carcinogenesi
Mucopolysaccharidosis Type IIIA: Clinical Spectrum and Genotype-Phenotype Correlations
Objective: Mucopolysaccharidosis (MPS) IIIA (Sanfilippo syndrome type A) is a lysosomal storage disorder caused by deficiency of the enzyme sulfamidase. Information on the natural course of MPS IIIA is scarce, but is much needed in view of emerging therapies. Methods: Clinical history and molecular defects of all 110 MPS IIIA patients identified by enzymatic studies in the Netherlands were collected and included in this study. Results: First clinical signs, mainly consisting of delayed speech development and behavioral problems, were noted between the ages of 1 and 6 years. Other symptoms included sleeping and hearing problems, recurrent upper airway infections, diarrhea, and epilepsy. The clinical course varied remarkably and could be correlated with the molecular defects. The frequent pathogenic mutations p.R245H, p.Q380R, p.S66W, and c.1080deIC were associated with the classical severe phenotype. Patients compound heterozygous for the p.S298P mutation in combination with 1 of the mutations associated with the classical severe phenotype had a significantly longer preservation of psychomotor functions and a longer survival. Two patients homozygous for the p.S298P mutation, and 4 patients from 3 families heterozygous for 3 missense variants not reported previously (p.T421R, p.P180L, and p.L12Q), showed a remarkably attenuated phenotype. Interpretation: We report the natural history and mutational analysis in a large unbiased cohort of MPS IIIA patients. We demonstrate that the Clinical spectrum of MPS IIIA is much broader than previously reported. A significant genotype-phenotype correlation was established in this cohort. ANN NEUROL 2010;68:876-88
Application of the New Classification on Patients with a Disorder of Sex Development in Indonesia
Disorder of sex development (DSD) patients in Indonesia most often do not receive a proper diagnostic evaluation and treatment. This study intended to categorize 88 Indonesian patients in accordance with the new consensus DSD algorithm. Diagnostic evaluation including clinical, hormonal, genetic, imaging, surgical, and histological parameters was performed. Fifty-three patients were raised as males, and 34 as females. Of 22 patients with 46, XX DSD, 15 had congenital adrenal hyperplasia, while in one patient, an ovarian Leydig cell tumor was found. In all 58 46, XY DSD patients, 29 were suspected of a disorder of androgen action (12 with an androgen receptor mutation), and in 9, gonadal dysgenesis was found and, in 20, severe hypospadias e.c.i. Implementation of the current consensus statement in a resource-poor environment is very difficult. The aim of the diagnostic workup in developing countries should be to end up with an evidence-based diagnosis. This is essential to improve treatment and thereby to improve the patients' quality of life
Clinical Study Application of the New Classification on Patients with a Disorder of Sex Development in Indonesia
Disorder of sex development (DSD) patients in Indonesia most often do not receive a proper diagnostic evaluation and treatment. This study intended to categorize 88 Indonesian patients in accordance with the new consensus DSD algorithm. Diagnostic evaluation including clinical, hormonal, genetic, imaging, surgical, and histological parameters was performed. Fifty-three patients were raised as males, and 34 as females. Of 22 patients with 46, XX DSD, 15 had congenital adrenal hyperplasia, while in one patient, an ovarian Leydig cell tumor was found. In all 58 46, XY DSD patients, 29 were suspected of a disorder of androgen action (12 with an androgen receptor mutation), and in 9, gonadal dysgenesis was found and, in 20, severe hypospadias e.c.i. Implementation of the current consensus statement in a resource-poor environment is very difficult. The aim of the diagnostic workup in developing countries should be to end up with an evidence-based diagnosis. This is essential to improve treatment and thereby to improve the patients' quality of life
Rapid detection of BRCA1 mutations by the protein truncation test
More than 75% of the reported mutations in the hereditary breast and ovarian cancer gene, BRCA1, result in truncated proteins. We have used the protein truncation test (PIT) to screen for mutations in exon 11, which encodes 61 % of BRCA1. In 45 patients from breast and/or ovarian cancer families we found six novel mutations: two single nucleotide insertions, three small deletions (1−5 bp) and a nonsense mutation identified two unrelated families. Furthermore, we were able to amplify the remaining coding region by RT−PCR using lymphocyte RNA. Combined with PTT, we detected aberrantly spliced products affecting exons 5 and 6 in one of two BRCA1−linked families examined. The protein truncation test promises to become a valuable technique in detecting BRCA1 mutations
BRCA1 genomic deletions are major founder mutations in Dutch breast cancer patients
To date, more than 300 distinct small deletions, insertions and point mutations, mostly leading to premature termination of translation, have been reported in the breast/ovarian-cancer susceptibility gene BRCA1. The elevated frequencies of some mutations in certain ethnic subpopulations are caused by founder effects, rather than by mutation hotspots. Here we report that the currently available mutation spectrum of BRCA1 has been biased by PCR-based mutation-screening methods, such as SSCP, the protein truncation test (PTT) and direct sequencing, using genomic DNA as template. Three large genomic deletions that are not detected by these approaches comprise 36% of all BRCA1 mutations found in Dutch breast-cancer families to date. A 510-bp Alu- mediated deletion comprising exon 22 was found in 8 of 170 breast-cancer families recruited for research purposes and in 6 of 49 probands referred to the Amsterdam Family Cancer Clinic for genetic counselling. In addition, a 3,835-bp Alu-mediated deletion encompassing exon 13 was detected in 6 of the 170 research families, while an deletion of approximately 14 kb was detected in a single family. Haplotype analyses indicated that each recurrent deletion had a single common ancestor
RAPID DETECTION OF BRCA1 MUTATIONS BY THE PROTEIN TRUNCATION TEST
More than 75% of the reported mutations in the hereditary breast and ovarian cancer gene, BRCA1, result in truncated proteins, We have used the protein truncation test (PTT) to screen for mutations in exon 11, which encodes 61% of BRCA1. In 45 patients from breast and/or ovarian cancer families we found six novel mutations: two single nucleotide insertions, three small deletions (1-5 bp) and a nonsense mutation identified two unrelated families, Furthermore, we were able to amplify the remaining coding region by RT-PCR using lymphocyte RNA. Combined with PTT, we detected aberrantly spliced products affecting exons 5 and 6 in one of two BRCA1-linked families examined. The protein truncation test promises to become a valuable technique in detecting BRCA1 mutations