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Biomedical subjects

P Lunt

Publications and source records attributed to P Lunt.

At least 19 recordsLinked to original sources
PubMed2001

Mutations in the general transcription factor TFIIH result in beta-thalassaemia in individuals with trichothiodystrophy.

The transcription factor TFIIH is involved in both basal transcription and DNA repair. Mutations in the XPD helicase component of TFIIH can result in the diverse clinical features associated with xeroderma pigmentosum (XP) and trichothiodystrophy (TTD). It is generally believed that the multi-system abnormalities associated with TTD are the result of a subtle deficiency in basal transcription. However, to date, there has been no clear demonstration of a defect in expression of any specific gene in individuals with these syndromes. Here we show that the specific mutations in XPD that cause TTD result in reduced expression of the beta-globin genes in these individuals. Eleven TTD patients with characterized mutations in the XPD gene have the haematological features of beta-thalassaemia trait, and reduced levels of beta-globin synthesis and beta-globin mRNA. All these parameters were normal in three patients with XP. These findings provide the first evidence for reduced expression of a specific gene in TTD. They support the hypothesis that many of the clinical features of TTD result from inadequate expression of a diverse set of highly expressed genes.

Cells, Cultured↗
PubMed1997

Nine novel L1 CAM mutations in families with X-linked hydrocephalus.

Mutations in the gene for neural cell adhesion molecule L1 are responsible for the highly variable phenotype found in families with X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type I. To date, 32 different mutations have been observed, the majority being unique to individual families. Here, we report nine novel mutations in L1 in 10 X-linked hydrocephalus families. Four mutations truncate the L1 protein and eliminate cell surface expression, and two would produce abnormal L1 through alteration of RNA processing. A further two of these mutations are small in-frame deletions that have occurred through a mechanism involving tandem repeated sequences. Together with a single missense mutation, these latter examples contribute to the growing number of existing mutations that affect short regions of the L1 protein that may have particular functional significance.

Amino Acid Sequence↗
PubMed1996

Prophylactic mastectomy for genetic predisposition to breast cancer: the proband's story.

The identification of the BRCA1 gene may prove a mixed blessing in the short term. First, the demand for testing might outstrip available resources, the ethics of testing are complex and the advice to give someone who tests positive is as yet unclear. Furthermore, the psychological dynamics within such families have not yet been considered seriously. As these families might be widespread, there will inevitably be problems involving clinical genetic centres in different parts of the country, or for that matter, in different areas of the world. In this paper we provide a case report, which might be considered an adumbration of things to come. The proband in this story (a co-author) was known to have inherited a genetic predisposition to cancer. This was because her identical twin had already developed the disease and she came from a kindred with a very high probability for carrying a dominant breast cancer gene in the germ line. We describe the personal reactions of an individual woman faced with these difficult decisions, the impact on her family and the impact on the clinical genetic services in different parts of the country. Our experience could help to provide a template for the development of regional services once genetic testing for predisposition to breast cancer becomes widely available.

Adult↗
PubMed1995

Germinal mosaicism in facioscapulohumeral muscular dystrophy (FSHD).

Facioscapulohumeral dystrophy (FSHD) is an autosomal-dominant neuromuscular disorder with a prevalence of 1 in 20,000. The DNA marker p13E-11 (D4F104S1) detects a de novo DNA rearrangement in the majority of sporadic and FSHD cases. These rearrangements consist of deletions of multiple copies of tandem repeat (D4Z4). We have studied 34 new mutation FSHD families of which 26 showed a de novo fragment with p13E-11. In three of the remaining eight families without a de novo fragment, germinal mosaicism was noted. In each case, the proband had inherited a small EcoR1 fragment from the clinically unaffected mother; however, the hybridization signal intensity of this fragment in the mother's DNA was significantly reduced in all three families. This is the first study to describe such mosaicism in FSHD families using DNA analysis and therefore has a considerable significance for genetic counseling and prenatal diagnosis.

Adolescent↗
PubMed1994

The association between Coffin-Lowry syndrome and psychosis: a family study.

This paper discusses a family presenting with features of Coffin-Lowry syndrome, namely abnormal facies, skeletal abnormalities and mental handicap. Two of the mildly affected females had psychotic illness with predominant depressive features, and all the severely affected males had profound sensorineural deafness.

Abnormalities, Multiple↗
PubMed1993

Complex mosaicism associated with trisomy 9.

Fetal karyotypes can be routinely obtained by chorionic villus biopsy, amniocentesis, or fetal blood sampling. Interpretation of results and subsequent counselling can be complicated by pseudomosaicism or mosaicism confined to the placenta or other tissues. We illustrate this by reporting a case of an abnormal fetus with a total of three karyotypically different cell lines (46,XX; 47,XX, +9; and 47,XX, +del(9) (q11) in different tissues (placenta, lung, gonad, and skin).

Abnormalities, Multiple↗
PubMed1992

Regional mapping of facioscapulohumeral muscular dystrophy gene on 4q35: combined analysis of an international consortium.

Members of an international consortium for linkage analysis of the facioscapulohumeral muscular dystrophy (FSHD) gene have pooled data for joint analyses, in an attempt to determine the precise location of the FSHD gene and the order of four DNA markers on 4q35 region. Six laboratories determined a total of 3,078 genotypes in 65 families, consisting of a total of 504 affected subjects and 559 unaffected subjects. For each marker, a mean of 648 meioses were informative. D4S139 and D4S163 were identified as the closest linked markers to the FSHD locus, with 99% upper confidence intervals of recombination fractions of .08 and .10, respectively. We have used the CRI-MAP program to construct the most likely order of cen-D4S171-F11-D4S163-D4S139-FSHD-tel, with favorable odds of 10(8)-10(114) over all other orders except that in which F11 and D4S171 are reversed, for which the odds ratio was 191:1. With this order, the genetic map of this region extends 25.5 cM in males and 13.8 cM in females (averaging 19.5 cM for sexes combined); the sex difference was statistically significant (P = .0013). Comparison between families for the two-point and multipoint lod scores involving FSHD showed no evidence for heterogeneity of this disorder. However, after the completion of this analysis, one large family which might show heterogeneity was identified. In view of this and the fact that all of the linked markers reside on the same side of the FSHD locus, the clinical application of these markers is not recommended at this time.

Chromosome Mapping↗
PubMed1992

The mapping of chromosome 4q markers in relation to facioscapulohumeral muscular dystrophy (FSHD).

Four DNA markers on the distal long arm of chromosome 4 have been analyzed for their linkage relationship to facioscapulohumeral muscular dystrophy (FSHD) in a series of 23 families with this disease. Two hypervariable markers, pH30 (D4S139) and EFD 139.1 (D4S184), both show close linkage with the disorder, with a maximum recombination fraction (theta max) of .02 and a maximum lod score (Zmax) of 36.77 and 34.50, respectively; two other markers, the locus for factor XI (F11) and the microsatellite marker Mfd22 (D4S171), both show less close linkage, with respective theta max of .16 (Zmax = 3.40) for F11 and .24 (Zmax = 1.61) for D4S171. While the relative ordering and orientation of the loci on the chromosome remain provisional, analysis of 15 individual recombination events in seven families supports the order D4S171-F11-D4S184-D4S139-FSHD, with the disease locus telomeric to all four markers.

Adolescent↗
PubMed1991

Aluminium sulphate in water in north Cornwall and outcome of pregnancy.

OBJECTIVE: To determine whether the excess aluminum sulphate accidentally added to the local water supply in north Cornwall in July 1988 had an adverse effect on the outcome of pregnancies. DESIGN: Outcomes of all singleton pregnancies in the affected area at the time of the incident (n = 92) were compared with those in two control groups: pregnancies in this area completed before the incident (n = 68) and pregnancies in a neighbouring area (n = 193). SUBJECTS: Mothers in the three groups, among whom there were 13 miscarriages, five terminations of pregnancy, and 336 live births. MAIN OUTCOME MEASURES: Fetal and perinatal loss, birth weight, gestation, obstetric complications, neonatal condition, and congenital defects. RESULTS: Among 88 pregnancies in women exposed to excess aluminum sulphate there was no excess of perinatal deaths (n = 0), low birthweight (n = 3), preterm delivery (n = 4), or severe congenital malformations (n = 0). There was, however, an increased rate of talipes in exposed fetuses (four cases, one control; p = 0.01). CONCLUSIONS: Because of small numbers it is not possible to say that high doses of aluminum sulphate are safe in pregnancy, but there is no evidence from this study of major problems apparent at birth.

Abnormalities, Drug-Induced↗
PubMed1991

Autosomal dominant inheritance of autoantibodies to thyroid peroxidase and thyroglobulin--studies in families not selected for autoimmune thyroid disease.

Recently the tendency to produce autoantibodies to thyroid peroxidase (TPO Ab) and thyroglobulin (Tg Ab) was shown to be inherited as an autosomal dominant characteristic in women but not in men. Because of potential bias in this study which was carried out in families with autoimmune thyroid disease (AITD), the inheritance of thyroid autoantibodies has been evaluated in 49 families unselected for autoimmune thyroid disease. Among these families (24 with facioscapulohumeral disease, 10 with Friedreich's ataxia, and 15 with schizophrenia) the prevalences of TPO Ab and Tg Ab were 27.8% and 26.7%, respectively, in women and 9.2% and 11.7%, respectively, in men. In 40 families where one or more individual had TPO Ab and/or Tg Ab, segregation analysis showed that the tendency to make antibodies was consistent with a Mendelian dominant trait in women but not in men. In young women, however, the prevalence of both TPO Ab and Tg Ab increased with age, rising from 14% and 10%, respectively, at age 15-24 to 35% and 40% at age 35-44. As this is inconsistent with a simple dominant hypothesis, a further segregation analysis by age was carried out in the families unselected for thyroid disease together with 16 pedigrees with AITD previously studied and two additional large AITD families. The results of the combined analysis provided strong support for the hypothesis of dominant inheritance but also showed significant reduction in gene expression among women aged 15-24 yr.

Adolescent↗
PubMed1989

An exclusion map for facioscapulohumeral (Landouzy-Déjérine) disease.

By using the genetic linkage data between the facioscapulohumeral muscular dystrophy (FSHD) gene and 57 markers on various autosomes, we have constructed an exclusion map for this disorder. The maximum likelihood location of the FSHD gene and the percentage of the excluded areas on each chromosome are presented here. This exclusion map shows that more than 80% of the genome has been excluded as a likely location of any locus responsible for FSHD in the majority of families. Chromosomes 3, 5, 10, 11, 15, and 19 remain largely unexcluded. Concentration on the highlighted areas of the genome should facilitate the identification of the site of the FSHD gene.

Chromosome Mapping↗
PubMed1989

Linkage analysis in the spinal muscular atrophy type of facioscapulohumeral disease.

Facioscapulohumeral disease is probably a heterogeneous disorder. We have ascertained and sampled two multigeneration families with the neurogenic form of this disorder, considered to be a type of spinal muscular atrophy (FSHSMA). The two families have 36 affected members. Linkage studies with 10 expressed and seven DNA restriction fragment length polymorphism (RFLP) markers failed to show significant linkage (Zmax greater than or equal to 3.00). However, two areas of probable linkage were defined on chromosomes 1p and 4q with the markers MNS (Zmax = 1.47 at theta max = 0.10) and PGM1 (Zmax = 0.94 at theta max = 0.001) respectively. We are using additional RFLPs from these and other areas of the human genome to screen these families for linkage to FSHSMA.

Chromosome Mapping↗
PubMed1989

Daughters whose mothers have anorexia nervosa: a pilot study of three adolescents.

In attempting to recruit mothers with anorexia nervosa and their adolescent daughters to participate in an interview study, we found that the majority of potentially suitable mothers refused to participate, fearing deleterious effects of the interviews on their relationships with their daughters. The three pairs who did participate were characterized by avoidant communication styles regarding the eating disorders, daughters focusing on what their mothers ate, mothers and daughters relating as close friends, and seemingly psychologically robust daughters. Additional research is needed to more carefully delineate the impact of maternal anorexia nervosa on the development of the children. As a matter of routine, clinicians should assess the children of patients with anorexia nervosa to institute preventive interventions, facilitate early case finding, and offer treatment where indicated.

Adolescent↗
PubMedDate not supplied

Cerebrospinal fluid cytokine levels after surgery with spinal or general anesthesia.

BACKGROUND AND OBJECTIVES: Studies show that pain may cause neuroinflammatory changes in the spinal cord. These inflammatory changes could be caused by circulating factors such as plasma cytokines or could be a primary neuroimmune response of the central nervous system following peripheral nerve injury. To identify the possible effects of peripheral trauma and pain on the cytokine environment of the spinal cord, interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations in plasma and cerebrospinal fluid (CSF) were measured before and after hip replacement surgery. METHODS: The investigation used a prospective, observational design to measure cytokine levels in samples of plasma and CSF by enzyme-linked immunosorbent assay (ELISA). Samples were taken from surgical patients before and after surgery under general anesthesia or spinal anesthesia performed with or without a spinal catheter. Reference samples were also obtained from healthy control subjects. RESULTS: Both plasma and CSF levels of IL-6 increased substantially after major surgery with either general or spinal anesthesia. No significant correlation was observed between plasma IL-6 and CSF IL-6 levels, suggesting a central origin for increased CSF cytokine levels. IL-10 did not change in plasma or CSF after surgery. Plasma and CSF IL-6 and IL-10 cytokine levels were very low or undetectable in healthy controls. CONCLUSIONS: Major orthopedic surgery leads to elevated CSF levels of the proinflammatory cytokine, IL-6. The origin of increased CSF IL-6 may be central because there was no significant correlation with plasma levels.

Anesthesia, General↗