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S J Bale

Publications and source records attributed to S J Bale.

At least 19 recordsLinked to original sources

A leucine----proline mutation in the H1 subdomain of keratin 1 causes epidermolytic hyperkeratosis.

Epidermolytic hyperkeratosis is an autosomal dominant disorder affecting the structural integrity of the suprabasal layers of human epidermis. We have recently documented in one family linkage of the disease phenotype to the cluster of type II keratins. We have now identified a leucine----proline amino acid substitution in the conserved H1 subdomain of keratin 1 that is present only in affected family members. Using a quantitative assay and electron microscopy with synthetic peptides, we show that, whereas the wild-type H1 peptide rapidly disassembles preformed keratin filaments in vitro, the mutant peptide does this far less efficiently. Therefore the mutation in keratin 1 is likely to cause defective keratin filaments and hence a defective cytoskeleton in the epidermal cells in vivo.

Amino Acid Sequence

Developmental defects in Gorlin syndrome related to a putative tumor suppressor gene on chromosome 9.

Gorlin syndrome is an autosomal dominant disorder that predisposes to basal cell carcinomas of the skin, ovarian fibromas, and medulloblastomas. Unlike other hereditary disorders associated with cancer, it features widespread developmental defects. To investigate the possibility that the syndrome is caused by mutation in a tumor suppressor gene, we searched for loss of heterozygosity in 16 sporadic basal cell carcinomas, 2 hereditary basal cell carcinomas, and 1 hereditary ovarian fibroma and performed genetic linkage studies in five Gorlin syndrome kindreds. Eleven sporadic basal cell carcinomas and all 3 hereditary tumors had allelic loss of chromosome 9q31, and all informative kindreds showed tight linkage between the Gorlin syndrome gene and a genetic marker in this region. Loss of heterozygosity at this chromosomal location, particularly in hereditary tumors, implies that the gene is homozygously inactivated and normally functions as a tumor suppressor. In contrast, hemizygous germline mutations lead to multiple congenital anomalies.

Basal Cell Nevus Syndrome

Genodermatoses with profound malignant potential.

There are a number of heritable disorders that have some association with skin cancer. Xeroderma pigmentosum, nevoid basal cell carcinoma syndrome, and familial melanoma and dysplastic nevi are three disorders associated with an extremely high rate of cutaneous malignancy. There is no known cure for these disorders, thus, patients and families need information about the disease process, treatment options, and guidelines aimed at prevention and early detection of skin cancer.

Basal Cell Nevus Syndrome

Linkage of epidermolytic hyperkeratosis to the type II keratin gene cluster on chromosome 12q.

We investigated the molecular genetics of epidermolytic hyperkeratosis (EHK), a dominant disorder characterized by epidermal blistering, hyperkeratosis, vacuolar degeneration and clumping of keratin filaments. Based on this pathology, we have excluded by linkage analysis several candidate genes for the disease; in contrast, complete linkage was obtained with the type II keratin, K1, on 12q11-q13. Linkage in this region of chromosome 12 was confirmed using several other markers, and multi-locus linkage analyses further supported this location. Keratins are excellent EHK gene candidates since their expression is specific to the suprabasal epidermal layers. In the pedigree studied here, a type II keratin gene, very probably K1, is implicated as the site of the molecular defect causing EHK.

Base Sequence

Relationship between head circumference and height in normal adults and in the nevoid basal cell carcinoma syndrome and neurofibromatosis type I.

Occipitofrontal circumference (OFC) was strongly correlated with height in 72 normal Caucasian men (r = 0.28, P = 0.018) and 78 women (r = 0.53, P less than 0.0001). OFC:height ratios were approximately normally distributed in each sex with a mean of 0.326 (standard deviation [sd] = 0.0139) in males and 0.335 (sd = 0.0177) in females. Relative macrocephaly (an OFC greater than the 95th centile for height) was seen in seven of nine probands with the nevoid basal cell carcinoma syndrome (NBCC), eight of 32 non-probands with NBCC, three of four neurofibromatosis type 1 (NF1) probands, and six of nine non-probands with NF1. Thirty-one percent of the non-proband NBCC cases had OFC less than the 50th centile for height, while none of the NF1 cases had this finding. Head size appears to be related to proband status in NBCC, while the evidence suggests that NF1 is a true macrocephaly syndrome. Objective detection of relative abnormalities in head size may aid in syndrome delineation and diagnosis.

Adult

Genetics of melanoma.

The goal of genetic analysis of malignant melanoma is to identify genes involved in the transformation of melanocytes and melanoma tumour progression. Three basic approaches have been used to analyze tumour progression in melanoma, and these include: (1) performing genetic linkage analysis on familial melanoma to identify the chromosomal location of genes which predispose individuals to melanoma; (2) examining tumours cytogenetically to identify frequently rearranged regions of the genome which presumably mark the location of genes involved in the evolution of melanoma; and (3) screening melanomas, using molecular techniques, to identify mutated oncogenes or tumour suppressor genes that play crucial roles in melanoma development. These studies provide strong evidence that genes on chromosomes 1, 6, 7 and 9 are involved in the aetiology of human melanoma.

Chromosome Aberrations

Re-evaluation of the linkage relationship between chromosome 11p loci and the gene for bipolar affective disorder in the Old Order Amish.

Reanalysis of an Old Order Amish pedigree, to include several new individuals and two changes in clinical status, markedly reduces the probability of linkage between bipolar affective disorder and the Harvey-ras-1 oncogene and insulin loci on chromosome 11. This linkage can be excluded using a large lateral extension of the original Amish pedigree.

Bipolar Disorder

Sister chromatid exchange and chromosome fragility in the nevoid basal cell carcinoma syndrome.

Previous studies of chromosome stability in the nevoid basal cell carcinoma syndrome have yielded inconsistent results and suffered from small sample sizes and less than optimal controls. We investigated chromosome fragility and sister chromatid exchange in 20 affected individuals from five multiplex pedigrees, and 15 first- or second-degree unaffected relatives. The percentage of case and control cells showing breaks or rearrangements was compared using a test of proportions. A similar procedure was used to compare site-specific sister chromatid exchanges in baseline cultures from affected persons and controls. No significant differences were noted for either chromosome fragility or sister chromatid exchange between the two groups. These results suggest that cancer susceptibility in the nevoid basal cell carcinoma syndrome is not caused by or manifested as chromosome instability.

4-Nitroquinoline-1-oxide

Mapping the gene for hereditary cutaneous malignant melanoma-dysplastic nevus to chromosome 1p.

We used molecular genetic techniques and multipoint linkage analyses to locate the gene responsible for cutaneous malignant melanoma-dysplastic nevus. We evaluated 99 relatives and 26 spouses in six families with a predisposition to melanoma. Thirty-four family members had cutaneous malignant melanoma, and 31 of these 34 also had histologically confirmed dysplastic nevi. Twenty-four family members had dysplastic nevi alone. An analysis of the cosegregation of the cutaneous malignant melanoma-dysplastic nevus trait with 26 polymorphic DNA markers on the short arm of chromosome 1 demonstrated the presence of a gene for susceptibility to melanoma. The gene was located between an anonymous DNA marker (D1S47) and the gene locus for pronatrodilatin, a commonly used reference gene (PND), in chromosome band 1p36. The odds were greater than 260,000:1 in favor of linkage at this location.

Adolescent

Availability of schizophrenic patients and their families for genetic linkage studies: findings from the Maryland epidemiology sample.

It has been suggested that collections of affected sib pairs, or their nuclear families, may be an efficient method for screening for genetic linkages in schizophrenia. We present the data collected in five years from 15 hospitals in the state of Maryland in an effort to determine if such a collection scheme will be feasible. Probands in our sample were eligible for inclusion in the sample if they were white, were age 16 years or older, and carried a research diagnosis of schizophrenia. Family data are reported for 258 probands. Using the most stringent category of affected (RDC schizophrenia) revealed ten families with two or more affected sibs. The broadest category of affected (any psychotic disorder or psychiatric hospitalization) identified only 36 families with two or more affected sibs. We conclude that, if schizophrenia is a heterogeneous disorder with decreased penetrance, an effort to collect multiplex nuclear families is unlikely to provide enough data to identify genetic linkage. Alternatively, an effort to seek out and collect larger multiplex, multigenerational families rather than a collection of affected sib pairs may be more efficacious.

Adolescent

Linkage analysis of multiple endocrine neoplasia type 1 with INT2 and other markers on chromosome 11.

We evaluated linkage between the locus for multiple endocrine neoplasia type 1 (MEN1) and several polymorphic DNA markers on chromosome 11 in a single large pedigree. On the basis of the finding of a basic fibroblast growth factor (bFGF)-like substance circulating in plasma of MEN1 patients, we chose a bFGF-related gene known to be localized to 11q13 as one of the markers. This gene locus, INT2, was found to be closely linked to the MEN1 gene. Pairwise and multipoint analyses with INT2 confirm the recent finding by C. Larsson et al. (1988, Nature (London) 332: 85-87) of MEN1 linkage to another marker, skeletal muscle glycogen phosphorylase, at 11q13.

Chromosomes, Human, Pair 11

Loss of alleles from the distal short arm of chromosome 1 occurs late in melanoma tumor progression.

The gene for familial malignant melanoma and its precursor lesion, the dysplastic nevus, has been assigned to a region of the distal short arm of chromosome 1, which is frequently involved in karyotypic abnormalities in melanoma cells. We have examined loci on chromosome 1p for loss-of-constitutional heterozygosity in 35 melanomas and 21 melanoma cell lines to analyze the role of these abnormalities in melanocyte transformation. Loss-of-heterozygosity at loci on chromosome 1p was identified in 15/35 (43%) melanomas and 11/21 (52%) melanoma cell lines. Analysis of multiple metastases derived from the same patient and of melanoma and lymphoblastoid samples from a family with hereditary melanoma showed that the loss-of-heterozygosity at loci on distal 1p is a late event in tumor progression, rather than the second mutation that would occur if melanoma were due to a cellular recessive mechanism. Comparisons with neuroblastoma and multiple endocrine neoplasia (MEN2) suggest that the frequent 1p loss-of-heterozygosity in these malignancies is a common late event of neuroectodermal tumor progression.

Alleles