A molecular variant of angiotensinogen is associated with diabetic nephropathy in IDDM.

Recent studies have suggested that an inherited predisposition to essential hypertension may increase susceptibility to nephropathy for patients with IDDM. Essential hypertension has been linked to the angiotensinogen (AGT) gene in genetic linkage studies in American and European populations. A molecular variant (M235T), which has a functional effect, has been described with highest plasma AGT levels being associated with the TT genotype. In a case-control study, we have evaluated the role of this functional genetic marker in patients with IDDM and nephropathy and in IDDM patients without nephropathy. We studied 195 IDDM patients, of whom 95 had established diabetic nephropathy; the remaining 100 patients, who had no evidence of microalbuminuria, served as control subjects. All patients were whites born in Northern Ireland. The point mutation in the AGT gene was analyzed using restriction typing. The background frequency of the M235T variant was assessed in 80 healthy blood donors, and the TT genotype was present in 9%. This genotype occurred in 8% of control IDDM patients without nephropathy and 19% of IDDM patients with nephropathy (P = 0.025). The odds ratio for diabetic nephropathy associated with the TT genotype was 2.7 (95% CI 1.04-7.52). There was no relationship between blood pressure and AGT genotypes in the control group. We cannot exclude the possibility that the observed association in the nephropathy group is due to an association between AGT genotype and hypertension. This evidence may help to explain the predisposition to diabetic nephropathy afforded by hypertension and merits further investigation.

A novel mutation in the helix termination peptide of keratin 5 causing epidermolysis bullosa simplex Dowling-Meara.

Epidermolysis bullosa simplex Dowling-Meara (MIM# 1317600) is the most severe of the three common epidermolysis bullosa simplex subtypes. In addition to the palmoplantar distribution seen in other epidermolysis bullosa simplex subtypes, extensive herpetiform blistering spontaneously develops on the trunk and limbs and may lead to scarring or milia formation. The keratin 5 and keratin 14 genes encode proteins that form the primary structural components of the basal epidermal keratinocytes, mutations in either of these genes can cause epidermolysis bullosa simplex. In this study we sequenced these genes in a family with epidermolysis bullosa simplex Dowling-Meara. We report a novel T to C transition in the helix termination peptide of K5 that causes a nonconservative substitution of a highly conserved amino acid within this critical region (I466T). This mutation adds to those previously reported and provides further evidence of phenotype-genotype correlation in epidermolysis bullosa simplex.

Mutations in keratin K9 in kindreds with epidermolytic palmoplantar keratoderma and epidemiology in Northern Ireland.

Epidermolytic palmoplantar keratoderma (EPPK, MIM #144200) is an autosomal dominant disorder in which hyperkeratosis confined to the palms and soles is characterized histologically by cytolysis of suprabasal keratinocytes. Mutations in the keratin 9 gene (KRT9), a type 1 keratin expressed exclusively in the suprabasal keratinocytes of palmoplantar epidermis, have previously been demonstrated in this disorder. Here, we have studied four Northern Irish kindreds presenting with EPPK. By direct sequencing of polymerase chain reaction products, heterozygous missense mutations in exon 1 of KRT9 were detected in all the families. These included a novel mutation M156T; as well as M156V in two kindreds; and R162Q in the remaining family. All mutations were confirmed by reverse strand sequencing and restriction enzyme analysis. The point prevalence of EPPK in Northern Ireland was found to be 4.4 per 100,000. To date, all reported EPPK mutations occur in the helix initiation motif at the start of the central coiled-coil rod domain of K9.

T-cell receptor alpha, beta, gamma, and delta chain gene microsatellites show no association with multiple sclerosis.

Genetic predisposition to multiple sclerosis (MS) is determined, in part, by certain HLA genotypes, but the contribution of T-cell receptor (TCR) germline polymorphisms to MS susceptibility is less clear. Reports of disease associations with restriction fragment length polymorphisms of TCR alpha and beta chain genes have been difficult to confirm, and little data is available on the influence of the TCR gamma delta germline in MS. We investigated the TCR alpha, beta, gamma, and delta chain genes of Northern Irish patients with MS using four microsatellite markers of high heterozygosity. There were similar allele frequencies in patients and controls for all microsatellites studied. We conclude there is no convincing evidence for an association of MS with TCR alpha, beta, gamma, and delta chain gene polymorphisms.

A novel single base deletion in the LDLR gene (211delG): Effect on serum lipid profiles and the influence of other genetic polymorphisms in the ACE, APOE and APOB genes.

A single base deletion (211delG) in the low density lipoprotein receptor (LDLR) gene was shown to cause familial hypercholesterolaemia (FH) in a large family from Northern Ireland. Twenty-four of 52 family members tested had this mutation, 13 of which were newly diagnosed. Mutation-positive individuals had significantly higher mean total-cholesterol (TC) and LDL-cholesterol (LDL-C) than those without 211delG. LDL-C was a more accurate indicator of disease status than TC. When TC levels alone were considered, in individuals over 16 years, a false negative rate (TC < 7.5 mmol/l) of 40% was found; however this fell to 13% based on inclusion of LDL-C levels. Individuals with coronary artery disease (CAD) had significantly higher TC levels than those without CAD and tended to have tendinous xanthomas (TX) and corneal arcus (CA). Generic polymorphisms in the angiotensin converting enzyme (ACE) and apolipoprotein (apo) B genes did not appear to be associated with lipid levels or with the clinical severity of the disease; however, the apo E epsilon4 allele did show a lipid-raising effect in individuals with the mutation.

The prevalence of inherited neuromuscular disease in Northern Ireland.

A comprehensive study of inherited neuromuscular disease was carried out in Northern Ireland between 1 February 1993 and 30 June 1994. Cases were ascertained from eight different sources and investigations and diagnoses were reviewed. Five hundred and forty three individuals were identified giving an overall prevalence of inherited neuromuscular disease of 1 in 2900 of the population. The prevalence of myotonic dystrophy was higher than that in most previously reported studies and accounted for 25% of all cases. Congenital myopathies were also found more frequently than expected. The overall prevalence compares well with that estimated by Emery from the reported prevalence rates of individual diseases.

Syndrome of partial aniridia, cerebellar ataxia, and mental retardation--Gillespie syndrome.

Here we describe a 5-year-old girl with Gillespie syndrome of cerebellar ataxia, partial aniridia, and mental retardation. The Gillespie syndrome probably is an autosomal recessive trait.

Orofaciodigital syndrome type IV: report of a patient.

We describe a further patient with the orofaciodigital syndrome type IV. The clinical characteristics include lobulated tongue, pseudo-cleft of lip, pre- and postaxial polydactyly of hands and feet, severe talipes equinovarus, mesomelic limb shortness associated with tibial hypoplasia, and severe bilateral deafness. Five similar cases including the present patient are now on record. Autosomal recessive inheritance is likely.

Polydactyly in a carrier of the gene for the Meckel syndrome.

Much of the Meckel syndrome literature has been concerned with the criteria for diagnosis but little has been said concerning heterozygote expression. We describe 3 affected brothers whose father and his paternal first cousin had postaxial polydactyly of both feet. A review of the literature was undertaken with regard to possible manifesting heterozygotes. We conclude that it is important to examine the relatives of patients with the Meckel syndrome for mild abnormalities, as these may be evidence of a manifesting heterozygote. Such information may be useful for genetic counselling.

Syndrome of short stature, microcephaly, mental retardation, and multiple epiphyseal dysplasia--Lowry-Wood syndrome.

We describe a brother and a sister with a syndrome of short stature, microcephaly, mental retardation, and multiple epiphyseal dysplasia. The parents were normal. This appears to be the second example of the syndrome first described by Lowry and Wood [1975] in two boys who had epiphyseal dysplasia, short stature, microcephaly, and nystagmus; one of these patients was mildly mentally retarded. The Lowry-Wood syndrome probably is an autosomal recessive trait.

Interstitial deletion 8p21.3----p23.1 in a 6-year-old girl.

We present a 6-year-old mentally retarded girl. Chromosome analysis showed an interstitial deletion of chromosome 8; 46,XX,del(8) (pter----p23.1::p21.3----qter). The proposita had normal activities of glutathione synthetase reductase (GSR) and factor VII. Parental chromosomes were normal.

Frontonasal dysostosis in two successive generations.

Frontonasal dysostosis (also called frontonasal "dysplasia") comprises ocular hypertelorism, median facial cleft affecting nose and/or upper lip, unilateral or bilateral cleft of the alae nasi, anterior cranium bifidum occultum, or a widow's peak. Usually it is a sporadic disorder, although a few familial cases have been reported. We describe a 2-year-old girl with anterior cranium bifidum occultum, lipoma of genu and anterior part of the corpus callosum, and hypertelorism. Her mother had a history of a nasal drip at birth caused by a defect in the cribriform plate and phenotypically, a widow's peak. This observation suggests either autosomal dominant or X-linked dominant inheritance. The family illustrates the importance of identifying mild expression of frontonasal dysostosis before genetic counseling.

Axial mesodermal dysplasia spectrum.

We report on a 4-month-old boy with manifestations of both the oculo-auriculovertebral spectrum and the caudal regression sequence. He has preauricular appendages, thoracic and lumbar hemivertebrae, anomalies of the ribs, dextrocardia, sacral "dysplasia," dislocated hips, bilateral talipes equinovarus, imperforate anus, recto-vesical fistula, malformed scrotum, and undescended testes. As suggested by Russell et al. [1981], who reported a patient with similar anomalies, the spectrum of anomalies probably is due to a generalized alteration in mesodermal cell migration during the primitive streak period. The term "axial mesodermal dysplasia spectrum" best describes the widespread anomalies in the cranial and caudal regions.

Oral-facial-digital syndrome with retinal abnormalities: OFDS type IX. A further case report.

The oral-facial-digital syndromes (OFDS) are a heterogeneous group. Recently, Gurrieri et al. [1992: Am J Med Genet 42:789-792] described a new OFDS characterised by typical oral, facial and digital abnormalities but distinguishable from previously reported OFDS by the presence of retinochoroidal lacunae of an apparently colobomatous origin. Toriello [1993: Clin Dysmorph 2:95-105] designated this possible new OFDS as Type IX. We describe a young woman presenting with oral, facial and digital anomalies and with the specific retinal abnormality reported by Gurrieri et al. [1992], thus confirming the existence of OFDS Type IX. As the patients of Gurrieri et al. [1992] were two affected brothers, they were unable to distinguish between autosomal and X-linked recessive inheritance. As our patient is an affected female, an autosomal recessive mode of inheritance is more likely.

Facio-cardio-renal (Eastman-Bixler) syndrome.

We report on a 5-year-old boy with moderate mental retardation, horseshoe kidneys, tricuspid valve prolapse, and a characteristic face with broad nasal root, prominent ears, and a cleft palate. These manifestations suggested the diagnosis of the Eastman-Bixler syndrome. Our patient also had an isolated growth hormone deficiency which responded successfully to treatment.

Congenital hypertrichosis, cardiomegaly and mild osteochondrodysplasia.

We report on a boy with congenital hypertrichosis, cardiomegaly and a mild osteochondrodysplasia, a rare syndrome of which there is only one previous report [Cantú et al., Hum Genet 60:36-41, 1982]. In all, five patients now are known to have this syndrome (2 females, 3 males). As the syndrome has been described in males and females and also in two sibs, inheritance is probably autosomal recessive.

Cleft lip and palate, hypertelorism, brachycephaly, flat facial profile, and congenital heart disease in three brothers.

A "new" syndrome was identified by McPherson and Clemens [1996: Am J Med Genet 62:58-60] in a brother and sister with bilateral cleft lip and palate, hypertelorism, flat facial profile, flat occiput, and complex heart defects. The brother also had a bilobed tongue and the sister had malrotation of the intestine and bifid thumbs. We describe three brothers with similar anomalies apart from the bilobed tongue, malrotation of the intestine, and bifid thumbs. McPherson and Clemens [1996: Am J Med Genet 62:58-60] suggested autosomal recessive inheritance. Our observation of three affected brothers also raises the possibility of X-linked recessive inheritance.

Cardiovascular abnormalities in the oculo-auriculo-vertebral spectrum (Goldenhar syndrome).

We describe the phenotypic characteristics of 25 individuals with oculo-auriculo-vertebral spectrum (OAVS) and its variants, seen in Northern Ireland between 1969-1989, with special reference to cardiovascular defects. We report the type and prevalence of cardiovascular findings and also estimate the minimum prevalence rate of OAVS to be 1 in 45,000.

Focal dermal hypoplasia (Goltz syndrome) associated with intestinal malrotation and mediastinal dextroposition.

Focal dermal hypoplasia (Goltz syndrome) is a rare syndrome comprising developmental anomalies of tissues and organs of mesoectodermal derivation. We report on a characteristic case of focal dermal hypoplasia with the previously unreported association of mediastinal dextroposition and intestinal malrotation.

First clinical case of small de novo duplication of 19q (13.3-13.4) confirmed by FISH.

Partial trisomy of 19q has been reported in only 13 patients, of which all but one have been due to unbalanced translocations. Only one previous report of a de novo duplication of distal 19q has been described in a fetal chorionic villus sample. There was no description of clinical phenotype in this report. We describe the clinical manifestations and cytogenetic analysis in a child with an inverted duplication of 19q 13.3 to 13.4 confirmed by FISH using a chromosome 19 whole chromosome probe. This case represents the first report of a liveborn with "pure" distal trisomy 19q. Findings defining this uncommon aneusomy are a flat facies, down turned mouth, abnormal ears, and a short neck with redundant skin folds.