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V P Sybert

Publications and source records attributed to V P Sybert.

At least 37 records · Page 2Linked to original sources
PubMed1995

A common keratin 5 gene mutation in epidermolysis bullosa simplex--Weber-Cockayne.

The Weber-Cockayne subtype of epidermolysis bullosa simplex is an inherited skin-fragility disorder characterized by basal keratinocyte lysis and epidermal blistering confined primarily to the hands and feet. The disorder results from a mutation in either the keratin 5 or keratin 14 gene, which encode the peptide components of the obligate heterodimeric keratin intermediate filaments of the basal cell. We have determined that a T-->G substitution mutation in keratin 5, which results in a Ile-->Ser change at codon 161, is common among patients with the Weber-Cockayne disease variant, accounting for six of 13 cases tested. The observed high frequency of this mutation may result from either a mutational hot spot or a founder effect. The potential utility of this common mutation in confirming disease status in some at-risk individual is discussed.

Base Sequence↗
PubMed1995

Psychosocial and sexual functioning in women with Turner syndrome.

Survey data on the sexual and social functioning of 80 adult women with Turner syndrome are described, as well as data regarding health status and self-concept. Each woman completed the Tennessee Self-Concept Scale, sections of the Derogatis Sexual Functioning Inventory, and a questionnaire covering a wide range of demographic and medical information. The women with Turner syndrome reported lower self-concept compared to a normative sample. Sexual attitudes, gender role identity, and body image were assessed. The women with Turner syndrome tended to exhibit more conservative sexual attitudes and a more negative body image. In contrast to a normative sample, the women with Turner syndrome were less likely to have been sexually active. In addition, those currently involved in a stable relationship reported a lower frequency of sexual intercourse compared to a normative sample, although they generally reported moderate to high levels of sexual satisfaction. Regression analyses revealed that health status was associated with self-concept, and that sexual satisfaction was related to both a higher frequency of intercourse and a higher self-reported health status.

Adult↗
PubMed1995

Epidermolysis bullosa simplex: a keratin 5 mutation is a fully dominant allele in epidermal cytoskeleton function.

To explore the relationship between abnormal keratin molecules, 10-nm intermediate filament (IF) organization, and epidermal fragility and blistering, we sought to determine the functional consequences of homozygosity for a dominant keratin defect. We describe a family with an autosomal dominant skin-blistering disorder, epidermolysis bullosa simplex, Koebner subtype (EBS-K), that has a novel point mutation, occurring in the keratin 5 gene (KRT5), that predicts the substitution of an evolutionarily conserved lysine by an asparagine residue (K173N). Unlike previous heterozygous mutations located within the initial segment of domain 1A of keratin molecules, K173N heterozygosity did not result in severe disease or clumping of keratin filaments. One family member was found to be homozygous for the K173N allele, having inherited it from each of her affected first-cousin parents. Despite a lack of normal keratin 5 molecules, and an effective doubling of abnormal molecules, available for heterodimerization with keratin 14 during IF formation, there were no significant differences in the clinical severity or the ultrastructural organization of the keratin IF cytoskeleton of the homozygous individual. These data demonstrate that the K173N mutation behaves as a fully dominant allele and indicate that a limited number of abnormal keratin molecules are sufficient to impair cytoskeletal function and elicit epidermal fragility and blistering.

Alleles↗
PubMed1995

Prenatal diagnosis of 45,X/46,XX mosaicism and 45,X: implications for postnatal outcome.

The prognosis for 45,X/46,XX mosaicism diagnosed prenatally has yet to be established. We report our experience with 12 patients in whom prenatal diagnosis of 45,X/46,XX mosaicism was detected by amniocentesis for advanced maternal age or decreased maternal serum alpha-feto protein and compared them with 41 45,X/46,XX patients diagnosed postnatally. The girls in the prenatal group range in age from 3 mo to 10 years. All have had normal linear growth. Four had structural anomalies including: ASD (n = 1); ptosis and esotropia (n = 1); labial fusion (n = 1); and urogenital sinus, dysplastic kidneys, and hydrometrocolpos (n = 1). Gonadotropins were measured in seven; one had elevated luteinizing hormone/FSH at 3 mo of age. One has developmental delay and seizures as well as ophthalmologic abnormalities. None would have warranted karyotyping for clinical suspicion of Turner syndrome. The prevalence of 45,X/46,XX mosaicism is 10-fold higher among amniocenteses than in series of postnatally diagnosed individuals with Turner syndrome, which suggests that most individuals with this karyotype escape detection and that an ascertainment bias exists toward those with clinically evident abnormalities. The phenomenon of a milder phenotype for the prenatal group is similar to that observed for 45,X/46,XY diagnosed prenatally. Prenatal counseling for 45,X/46,XX in the absence of such ultrasound abnormalities as hydrops fetalis should take into account the expectation of a milder phenotype (except, possibly, with respect to developmental delay) than that of patients ascertained postnatally. The same does not hold true for 45,x diagnosed prenatally.

Amniocentesis↗
PubMed1994

Hypomelanosis of Ito: a description, not a diagnosis.

The term hypomelanosis of Ito has been used as a diagnosis for individuals with hypopigmentation or depigmentation distributed along the lines of Blaschko. Approximately half of these patients have had neurologic, skeletal, and/or ocular abnormalities. In many, determination that the lighter areas of skin were hypopigmented rather than the darker areas hyperpigmented has been arbitrary. Evidence documenting single-gene transmission is unconvincing and recurrence risks appear to be negligible in most instances. Karyotyping of blood lymphocytes, skin fibroblasts, and/or keratinocytes of 115 individuals reported in the literature revealed abnormal chromosome constitutions in 60. Three patients were 46,XX/46,XY chimeras, two were 46XX/46,XX chimeras. Most patients were mosaic for aneuploidy or unbalanced translocations, with two or more chromosomally distinct cell lines either within the same tissue or between tissues. The more common alterations included mosaic trisomy 18, diploidy/triploidy, mosaicism for sex chromosome aneuploidy, and tetrasomy 12p. Karyotyping of blood and, if necessary, skin, to detect mosaicism is warranted in all patients presenting with swirley pigmentary changes, either hyperpigmentation or hypopigmentation. The terms hypomelanosis of Ito and incontinentia pigmenti achromians should be abandoned as they are neither diagnostic or specific.

Adolescent↗
PubMed1993

Prenatal detection of epidermolysis bullosa letalis with pyloric atresia in a fetus by abnormal ultrasound and elevated alpha-fetoprotein.

We report on the prenatal diagnosis of epidermolysis bullosa letalis with pyloric atresia in a pregnancy not known to be at risk for this condition. Elevated maternal serum alpha-fetoprotein levels led to ultrasonography which demonstrated gastric dilatation, consistent with pyloric atresia, and echogenic particles in the amniotic fluid, the "snowflake sign," previously described in two pregnancies of fetuses with disorders of skin sloughing. Amniotic fluid alpha-fetoprotein was markedly elevated and the acetylcholinesterase was positive. The diagnosis of epidermolysis bullosa letalis with pyloric atresia was confirmed after delivery by electron microscopy of fetal skin which showed typical changes of hypoplastic absent hemidesmosomes and separation along the dermal-epidermal junction. None of these abnormal prenatal findings are consistently present in pregnancies with epidermolysis bullosa with pyloric atresia. Thus, although useful when abnormal, when the test results are normal, the need for confirmatory fetoscopy and fetal skin biopsy remains.

Abnormalities, Multiple↗
PubMed1993

A keratin 14 mutational hot spot for epidermolysis bullosa simplex, Dowling-Meara: implications for diagnosis.

Recently, two patients with the Dowling-Meara subtype of epidermolysis bullosa simplex (EBS-DM) were reported with different mutations in codon 125 of the keratin 14 gene. To determine whether these are common mutations, we screened ten EBS-DM patients and their families using single nucleotide primer extension. Four of ten unrelated EBS-DM patients had a G-->A substitution at base pair 434 of codon 125, whereas one case out of ten had a C-->T substitution at position 433 of the same codon. The G434A alteration cosegregated with the disorder in two multigenerational families; no recombination events were detected. In these two families, linkage analysis provided significant evidence in favor of linkage between G434A and the EBS-DM phenotype, with a LOD score of 3.29 at a recombination rate of 0%. Codon 125 substitutions identified in three unrelated sporadic EBS-DM patients were not found in their clinically unaffected parents. Together, these data provide compelling genetic evidence that the codon 125 substitutions are causal for EBS-DM. The high frequency of mutation at this site in individuals with EBS-DM now makes DNA-based diagnosis of this disorder feasible.

Amino Acid Sequence↗
PubMed1993

Severe skin erosions and scalp infections in AEC syndrome.

Hay-Wells syndrome is an autosomal dominant condition characterized by ankyloblepharon filiforme adnatum, ectodermal dysplasia, and cleft palate with or without associated cleft lip (AEC syndrome). Although several reported patients had eroded skin at birth and recurrent scalp infections, these are not generally regarded as major features of the disorder. In our experience, denuded skin at birth and chronic scalp erosions complicated by infection are common features of this syndrome. Aggressive wound care in conjunction with early administration of topical or systemic antibiotics is suggested.

Abnormalities, Multiple↗
PubMed1993

Principles of genetics in the molecular era. A primer for dermatologists.

Advances in technology have resulted in an explosion of information about the molecular bases of human inheritance and human disease. Much of the new terminology is daunting, and it is becoming increasingly difficult to remain current. This article briefly reviews some of the changes in our understanding of the rules of inheritance and recurrence risks for genetic disorders. Further readings are suggested, and a glossary of technical terms is provided.

Chromosome Aberrations↗
PubMed1992

Preferential mutation of the neurofibromatosis type 1 gene in paternally derived chromosomes.

An interesting feature of neurofibromatosis type 1 (NF1) is its high mutation rate of 1 x 10(-4) per gamete per generation. The molecular basis for frequent NF1 mutation in unknown; the gene is not deletion prone. We have found that in all ten families examined, the apparent new NF1 mutation occurred on the paternally-derived chromosome. The probability of observing this result by chance is less than 0.001 assuming an equal frequency of mutation of paternal and maternal NF1 genes. We hypothesize a role for genomic imprinting that may either enhance mutation of the paternal NF1 gene or confer protection from mutation to the maternal NF1 gene.

Chromosomes, Human↗
PubMed1992

Prenatal diagnosis of severe dermatologic diseases.

It is obvious that the nature of prenatal diagnosis of severe or lethal skin conditions is rapidly evolving. New molecular, enzymatic, and ultrastructural markers will become available. The biochemical base of many of these disorders will become known and the accuracy and utility of in utero diagnosis will improve. We wish to make one point again. The field is rapidly outpacing the ability of review articles to keep current. We urge you to refer to a genetic center for information when you are dealing with a situation in which prenatal diagnosis may be an issue.

Amniocentesis↗
PubMed1990

Pigmentary abnormalities and mosaicism for chromosomal aberration: association with clinical features similar to hypomelanosis of Ito.

Thirteen patients with hypopigmentation of the skin characteristic of hypomelanosis of Ito, and with developmental disabilities or structural malformations, or both, were examined at our center. Eight were found to have abnormal karyotypes in lymphocytes, fibroblasts, or both. No single clinical feature was predictive of chromosome imbalance in this group of patients. Cytogenetic findings included a balanced de novo X-autosome translocation; ring 10; 45,X/46,X,+ring; mosaic del 13q11 (fibroblasts); mosaic triploidy (fibroblasts); mosaic tetrasomy 12p (fibroblasts); mosaic apparently balanced 15;22 translocation (peripheral blood); and mosaic trisomy 18 (peripheral blood). Hypomelanosis of Ito is characterized by swirly hypopigmentation or depigmentation of the skin with or without other malformations. Autosomal dominant, autosomal recessive, and X-linked dominant inheritance have been suggested but not confirmed. Chromosomal aneuploidy has also been reported. We believe that hypomelanosis of Ito is an etiologically heterogeneous physical finding, and recommend karyotyping of multiple tissues of all patients with abnormal cutaneous pigmentation associated with developmental delay or structural malformations.

Adolescent↗