The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
S.a. Cuevas-covarrubias - One of the best experts on this subject based on the ideXlab platform.
-
Deletion of eXons 1-5 of the STS gene causing X-Linked Ichthyosis
The Journal of investigative dermatology, 2001Co-Authors: Margarita Valdés-flores, Susana Kofman-alfaro, A. L. Jimenez Vaca, S.a. Cuevas-covarrubiasAbstract:X-Linked Ichthyosis is an inherited disorder due to steroid sulfatase deficiency. It is clinically characterized by dark, adhesive, and regular scales of the skin. Most X-Linked Ichthyosis patients present large deletions of the STS gene and flanking markers; a minority show a point mutation or partial deletion of the STS gene. In this study we analyzed the STS gene in a family with simultaneous occurrence of X-Linked Ichthyosis and Ichthyosis vulgaris. X-Linked Ichthyosis diagnosis was confirmed through steroid sulfatase assay in leukocytes using 7-[ 3 H]-dehydroepiandrosterone sulfate as a substrate. EXons 1, 2, 5, and 6–10, and the 5′ flanking markers DXS1130, DXS1139, and DXS996 of the STS gene were analyzed by polymerase chain reaction. X-Linked Ichthyosis patients of the family (n = 4 males) had undetectable levels of STS activity (0.00 pmol per mg protein per h). The DNA analysis showed that only eXons 6–10 and the 5′ flanking markers of the STS gene were present. We report the first partial deletion of the STS gene spanning eXons 1–5 in X-Linked Ichthyosis patients.
-
A Novel Partial Deletion of EXons 2–10 of the STS Gene in Recessive X-Linked Ichthyosis
The Journal of investigative dermatology, 2000Co-Authors: Margarita Valdés-flores, Susana Kofman-alfaro, A. L. Jimenez Vaca, S.a. Cuevas-covarrubiasAbstract:X-Linked Ichthyosis is an inherited disease due to steroid sulfatase deficiency. Onset is at birth or early after birth with dark, regular, and adherent scales of skin. ApproXimately 85%-90% of X-Linked Ichthyosis patients have large deletions of the STS gene and flanking sequences. Three patients have been identified with partial deletions of the gene. Two deletions have been found at the 3′ eXtreme and the other one implicating eXons 2–5. This study describes a novel partial deletion of the STS gene in an X-Linked Ichthyosis patient. The subject was classified through steroid sulfatase assay in leukocytes using 7-[ 3 H]-dehydroepiandrosterone sulfate as a substrate. EXons 1, 2, 5, and 7–10, and 3′ flanking sequences DXS1131, DXS1133, DXS237, DXS1132, DXF22S1, and DXS278 of the STS gene were analyzed through polymerase chain reaction. The DNA analysis showed that eXon 1 and 3′ flanking sequences from DXS237 to DXS278 were present. In this study we report the fourth partial deletion of the STS gene and the first spanning eXons 2–10 in X-Linked Ichthyosis patients.
-
Most "sporadic" cases of X-Linked Ichthyosis are not de novo mutations.
Acta dermato-venereologica, 1999Co-Authors: S.a. Cuevas-covarrubias, Margarita Valdés-flores, E Orozco Orozco, Juan C. Díaz-zagoya, Susana Kofman-alfaroAbstract:X-Linked Ichthyosis is an inherited disease with dark, regular and adherent scales as clinical characteristics. It is caused by a deficiency of the steroid sulphatase enzyme. Steroid sulphatase assay is a relative easy tool that enables correct diagnosis of X-Linked Ichthyosis patients and carriers. A large number of X-Linked Ichthyosis patients correspond to non-familial cases that seem to represent de novo mutations. In this study, we eXamined the X-Linked Ichthyosis carrier state of the mothers of 42 non-familial cases to determine whether their children corresponded to de novo mutations. To classify patients and carriers, a steroid sulphatase assay was performed in leukocytes using 7-[3H]-dehydroepiandrosterone sulphate as substrate. In 36 mothers (85%) we found steroid sulphatase activity compatible with the carrier state of X-Linked Ichthyosis. This data suggest that most of the mothers of these patients present the primary gene defect, eXcluding de novo mutations in the patients.
Debashis Ghosh - One of the best experts on this subject based on the ideXlab platform.
-
Mutations in X-Linked Ichthyosis disrupt the active site structure of estrone/DHEA sulfatase
Biochimica et biophysica acta, 2004Co-Authors: Debashis GhoshAbstract:X-Linked Ichthyosis is an inherited genetic disorder of the skin that results from steroid sulfatase (STS) deficiency. Seven critical point mutations have been previously reported for the STS gene, siX leading to amino acid substitutions and one to a premature termination of the polypeptide chain. The three-dimensional structure of the full-length human enzyme has been recently determined. Amino acid substitutions due to point mutations in X-Linked Ichthyosis are mapped onto the three-dimensional structure of human STS. In each case, the substitution appears to cause disruption of the active site architecture or to interfere with the enzyme's putative membrane-associating motifs crucial to the integrity of the catalytic cleft, thereby providing an eXplanation for the loss of STS activity.
-
mutations in X Linked Ichthyosis disrupt the active site structure of estrone dhea sulfatase
Biochimica et Biophysica Acta, 2004Co-Authors: Debashis GhoshAbstract:X-Linked Ichthyosis is an inherited genetic disorder of the skin that results from steroid sulfatase (STS) deficiency. Seven critical point mutations have been previously reported for the STS gene, siX leading to amino acid substitutions and one to a premature termination of the polypeptide chain. The three-dimensional structure of the full-length human enzyme has been recently determined. Amino acid substitutions due to point mutations in X-Linked Ichthyosis are mapped onto the three-dimensional structure of human STS. In each case, the substitution appears to cause disruption of the active site architecture or to interfere with the enzyme's putative membrane-associating motifs crucial to the integrity of the catalytic cleft, thereby providing an eXplanation for the loss of STS activity.
Fumio Kaneko - One of the best experts on this subject based on the ideXlab platform.
-
Novel point mutations in the steroid sulfatase gene in patients with X-Linked Ichthyosis: transfection analysis using the mutated genes.
The Journal of investigative dermatology, 2000Co-Authors: Noritaka Oyama, Masataka Satoh, Keiji Iwatsuki, Fumio KanekoAbstract:X-Linked Ichthyosis is caused by steroid sulfatase deficiency which results from abnormalities in its coding gene. The majority of X-Linked Ichthyosis patients (≈90%) have complete or partial deletions of the steroid sulfatase gene. In this study, we eXamined the mutations of the steroid sulfatase gene in two unrelated X-Linked Ichthyosis patients without complete deletion of the gene. Polymerase chain reaction–single-strand conformation polymorphism and direct sequencing analyses showed that each patient has a different single base pair substitution within eXon 8 encoding the C-terminal half of the steroid sulfatase polypeptide. Both mutations resulted in the transversion of functional amino acids: a G→C substitution at nucleotide 1344, causing a predicted change of a glycine to an arginine, and a C→T substitution at nucleotide 1371, causing a change from a glutamine to a stop codon. In vitro steroid sulfatase cDNA eXpression using site-directed mutagenesis revealed that these mutations are in fact pathogenic and reflect the levels of steroid sulfatase enzyme activities in each of the X-Linked Ichthyosis patients.
Ishibashi - One of the best experts on this subject based on the ideXlab platform.
-
Deletion pattern of the steroid sulphatase gene in Japanese patients with X-Linked Ichthyosis
The British journal of dermatology, 1998Co-Authors: Saeki, Kuwata, Nakagawa, Shimada, Tamaki, IshibashiAbstract:Most caucasian patients with X-Linked Ichthyosis (XLI) reportedly display large genomic deletions involving the entire steroid sulphatase (STS) gene and flanking regions. In this study, we investigated the deletion patterns of the STS gene and flanking regions in 12 unrelated Japanese patients with XLI using the polymerase chain reaction method with 10 markers, including the 5' and 3' ends of the STS gene. Eleven of the 12 patients eXhibited deletion of this entire gene, whereas the twelfth patient showed no evidence of deletion. In 10 of the 12 patients, the entire region from DXS1139 to DXF22S1 was deleted, the most common deletion pattern observed in caucasian patients, indicating that there are no racial or ethnic differences.
Margarita Valdés-flores - One of the best experts on this subject based on the ideXlab platform.
-
Deletion of eXons 1-5 of the STS gene causing X-Linked Ichthyosis
The Journal of investigative dermatology, 2001Co-Authors: Margarita Valdés-flores, Susana Kofman-alfaro, A. L. Jimenez Vaca, S.a. Cuevas-covarrubiasAbstract:X-Linked Ichthyosis is an inherited disorder due to steroid sulfatase deficiency. It is clinically characterized by dark, adhesive, and regular scales of the skin. Most X-Linked Ichthyosis patients present large deletions of the STS gene and flanking markers; a minority show a point mutation or partial deletion of the STS gene. In this study we analyzed the STS gene in a family with simultaneous occurrence of X-Linked Ichthyosis and Ichthyosis vulgaris. X-Linked Ichthyosis diagnosis was confirmed through steroid sulfatase assay in leukocytes using 7-[ 3 H]-dehydroepiandrosterone sulfate as a substrate. EXons 1, 2, 5, and 6–10, and the 5′ flanking markers DXS1130, DXS1139, and DXS996 of the STS gene were analyzed by polymerase chain reaction. X-Linked Ichthyosis patients of the family (n = 4 males) had undetectable levels of STS activity (0.00 pmol per mg protein per h). The DNA analysis showed that only eXons 6–10 and the 5′ flanking markers of the STS gene were present. We report the first partial deletion of the STS gene spanning eXons 1–5 in X-Linked Ichthyosis patients.
-
A Novel Partial Deletion of EXons 2–10 of the STS Gene in Recessive X-Linked Ichthyosis
The Journal of investigative dermatology, 2000Co-Authors: Margarita Valdés-flores, Susana Kofman-alfaro, A. L. Jimenez Vaca, S.a. Cuevas-covarrubiasAbstract:X-Linked Ichthyosis is an inherited disease due to steroid sulfatase deficiency. Onset is at birth or early after birth with dark, regular, and adherent scales of skin. ApproXimately 85%-90% of X-Linked Ichthyosis patients have large deletions of the STS gene and flanking sequences. Three patients have been identified with partial deletions of the gene. Two deletions have been found at the 3′ eXtreme and the other one implicating eXons 2–5. This study describes a novel partial deletion of the STS gene in an X-Linked Ichthyosis patient. The subject was classified through steroid sulfatase assay in leukocytes using 7-[ 3 H]-dehydroepiandrosterone sulfate as a substrate. EXons 1, 2, 5, and 7–10, and 3′ flanking sequences DXS1131, DXS1133, DXS237, DXS1132, DXF22S1, and DXS278 of the STS gene were analyzed through polymerase chain reaction. The DNA analysis showed that eXon 1 and 3′ flanking sequences from DXS237 to DXS278 were present. In this study we report the fourth partial deletion of the STS gene and the first spanning eXons 2–10 in X-Linked Ichthyosis patients.
-
Most "sporadic" cases of X-Linked Ichthyosis are not de novo mutations.
Acta dermato-venereologica, 1999Co-Authors: S.a. Cuevas-covarrubias, Margarita Valdés-flores, E Orozco Orozco, Juan C. Díaz-zagoya, Susana Kofman-alfaroAbstract:X-Linked Ichthyosis is an inherited disease with dark, regular and adherent scales as clinical characteristics. It is caused by a deficiency of the steroid sulphatase enzyme. Steroid sulphatase assay is a relative easy tool that enables correct diagnosis of X-Linked Ichthyosis patients and carriers. A large number of X-Linked Ichthyosis patients correspond to non-familial cases that seem to represent de novo mutations. In this study, we eXamined the X-Linked Ichthyosis carrier state of the mothers of 42 non-familial cases to determine whether their children corresponded to de novo mutations. To classify patients and carriers, a steroid sulphatase assay was performed in leukocytes using 7-[3H]-dehydroepiandrosterone sulphate as substrate. In 36 mothers (85%) we found steroid sulphatase activity compatible with the carrier state of X-Linked Ichthyosis. This data suggest that most of the mothers of these patients present the primary gene defect, eXcluding de novo mutations in the patients.
