Detection of Carriers for X-linked Ichthyosis by Southern Blot Analysis and Identification of One Family with a De Novo Mutation

Bonifas, Jeannette M.; Epstein, Ervin

doi:10.1111/1523-1747.ep12872703

Cited by 20 publications

(7 citation statements)

References 33 publications

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“…In a previous report, 4 mothers of 5 unrelated sporadic Mexican cases of XLI showed an STS activity compatible with a carrier state, indicating that they presented the primary gene defect (16). In another report, the XLI carrier state was demonstrated in the mother of a patient classi¢ed as a de novo mutation (17). The aim of the present study was to corroborate in a larger group of XLI sporadic cases that most of them do not correspond to de novo mutations.…”

supporting

confidence: 53%

“…We also found in 7 families normal STS activity in all sisters of the XLI carriers, supporting the fact that the patients' mothers su¡ered the primary gene defect. In a previous report, an XLI individual case was analysed and the authors state that the gene defect of STS arose on an allele inherited from the proband's clinically normal maternal grandfather (17). It would be interesting to determine in more cases whether the maternal or paternal X-chromosome with the gene defect is transmitted to the XLI carrier mother.…”

Section: Resultsmentioning

confidence: 99%

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Most "Sporadic" Cases of X-linked Ichthyosis are not De Novo Mutations

Valdés-Flores²,

E³

et al. 1999

Acta Dermato-Venereologica

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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.

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supporting

confidence: 53%

Section: Resultsmentioning

confidence: 99%

Most "Sporadic" Cases of X-linked Ichthyosis are not De Novo Mutations

Valdés-Flores²,

E³

et al. 1999

Acta Dermato-Venereologica

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“…The genetic methods of diagnosis have also brought a considerable improvement in the detection of carriers, although they have not yet been fully developed. Some authors report satisfactory results on comparing the differences between the genetic load of affected subjects, heterozygotic carriers and normal women by Southern blot and densitometry 111 . Others have successfully used in situ hybridization for the diagnosis of carriers 10 and PCR with high‐performance liquid chromatography 112 .…”

Section: Laboratory Diagnosis Of X‐linked Ichthyosismentioning

confidence: 99%

X-linked ichthyosis: an update

Hernández‐Martín¹,

González-Sarmiento²,

P³

1999

British Journal of Dermatology

141

122

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X-linked ichthyosis is a genetic disorder of keratinization characterized by a generalized desquamation of large, adherent, dark brown scales. Extracutaneous manifestations include corneal opacity and cryptorchidism. Since 1978 it has been known that a deficit in steroid sulphatase enzyme (STS) is responsible for the abnormal cutaneous scaling, although the exact physiological mechanism remains uncertain. The STS gene has been mapped to the distal part of the short arm of the X chromosome. Interestingly, this region escapes X chromosome inactivation and has the highest ratio of chromosomal deletions among all genetic disorders, complete deletions having been found in up to 90% of patients. Diagnosis of patients with X-linked ichthyosis and female carriers is based on biochemical and genetic analysis. The latter currently seems to be the most accurate method in the majority of cases.

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“…Thirty of 40 patients (72.5%) were carriers of complete deletions (lack of exons 1, 5 and 10). Examples from other series have revealed complete deletions in 14 of 15 patients with RXLI; 14 in eight of eight patients, 15 and in eight of 10 patients. 9 In fact, a global 90% frequency of complete deletions of the STS gene in patients with RXLI has been reported previously.…”

Section: Resultsmentioning

confidence: 84%