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Biomedical subjects

A Fryer

Publications and source records attributed to A Fryer.

At least 55 records · Page 3Linked to original sources
PubMed1996

The cutaneous features of tuberous sclerosis: a population study.

We report the cross-sectional age-related prevalence of cutaneous features of the tuberous sclerosis complex in a defined population. Of 131 affected individuals, 126 (96%) exhibited skin signs. Although there is considerable variation in the age of expression of all the skin lesions, there is a trend towards the earlier expression of hypomelanic macules and forehead fibrous plaques compared with facial angiofibromas and ungual fibromas. Shagreen patches are usually present by puberty. Ungual fibromas appeared for the first time as late as the fifth decade and were the only clinical feature in three individuals. Gum fibromas were present in 36%. Ten individuals (8%) presented because of the skin manifestations and 21% received treatment for symptomatic skin lesions. Two individuals had large hamartomas at unusual sites (occiput and forearm).

Adolescent↗
PubMed1995

Mutational analysis of familial and sporadic hyperekplexia.

Hyperekplexia is a rare, autosomal dominant neurological disorder characterized by hypertonia, especially in infancy, and by an exaggerated startle response. This disorder is caused by mutations in the alpha 1 subunit of the inhibitory glycine receptor (GLRA1). We previously reported two GLRA1 point mutations detected in 4 unrelated hyperekplexia families; both mutations were at nucleotide 1192 and resulted in the replacement of Arg271 by a glutamine (R271Q) in one case and a leucine (R271L) in the other. Here, 5 additional hyperekplexia families are shown to have the most common G-to-A transition mutation at nucleotide 1192. Haplotype analysis using polymorphisms within and close to the GLRA1 locus suggests that this mutation has arisen at least twice (and possibly four times). In 2 additional families, a third mutation is also presented that changes a tyrosine at amino acid 279 to a cysteine (Y279C). Five patients with atypical clinical features and equivocal or absent family history of hyperekplexia and 1 patient with a classical presentation but not family history are presented in whom a mutation in the GLRA1 gene was not detected. Thus, only clinically typical hyperekplexia appears to be consistently associated with GLRA1 mutations, and these affect a specific extracellular domain of the protein.

Base Sequence↗
PubMed1995

The role of molecular genetics in the prenatal diagnosis of retinal dystrophies.

Inherited retinal dystrophies are important causes of incurable blindness in developed countries. Advances in molecular genetics promise significant improvements in their management. Immediate benefits of present knowledge are presymptomatic and prenatal diagnosis in selected cases. To study the predictive power of these techniques a simulated genetic risk estimation was undertaken in a cone-rod retinal dystrophy pedigree known to be linked to chromosome 19. Using data on five fully informative, flanking DNA markers, phenotype was correctly assigned with only a 2% probability of error. If the two most closely linked markers were found to be uninformative, this error probability remained unchanged. Using genetic risk calculations and direct mutation detection many retinal dystrophies could now be identified by prenatal diagnosis.

Blindness↗
PubMed1995

Definition of the blepharophimosis, ptosis, epicanthus inversus syndrome critical region at chromosome 3q23 based on the analysis of chromosomal anomalies.

Blepharophimosis syndrome (BPES) is an autosomal dominant disorder of craniofacial development, the features of which are small palpebral fissures (blepharophimosis), drooping eyelids (ptosis) and a skin fold arising from the lower eyelid (epicanthus inversus). The chromosomal localization and identity of the BPES locus is not known with certainty. In the current paper, DNA samples from three individuals with a clinical history of BPES, two with interstitial deletions (cases 1 and 2) and one with a balanced translocation (case 3) all involving chromosome 3q23, were analyzed. Allele loss studies using short tandem repeat markers in cases 1 and 2 suggested that the region between the markers D3S1292 and D3S1306 was deleted in both cases. Subsequently, the derived chromosomes resulting from the translocation in case 3 were segregated in interspecific somatic cell hybrids. Analysis of the resultant hybrids showed that D3S1615 was retained in the derived chromosome 3, whereas D3S1316 was retained in the derived chromosome 4. In neither case was the marker present in the reciprocal hybrid. These results indicate that the BPES critical region lies in the D3S1615-D3S1316 interval.

Abnormalities, Multiple↗
PubMed1995

Vaginal rhabdomyosarcoma in a patient with Noonan syndrome.

This is the first report of a Noonan syndrome patient who has had a vaginal rhabdomyosarcoma. Recent reports of Noonan syndrome patients with leukaemia have prompted speculation that there may be a slightly increased malignancy risk associated with this syndrome.

DNA Mutational Analysis↗
PubMed1995

New domains of neural cell-adhesion molecule L1 implicated in X-linked hydrocephalus and MASA syndrome.

The neural cell-adhesion molecule L1 is involved in intercellular recognition and neuronal migration in the CNS. Recently, we have shown that mutations in the gene encoding L1 are responsible for three related disorders; X-linked hydrocephalus, MASA (mental retardation, aphasia, shuffling gait, and adducted thumbs) syndrome, and spastic paraplegia type I (SPG1). These three disorders represent a clinical spectrum that varies not only between families but sometimes also within families. To date, 14 independent L1 mutations have been reported and shown to be disease causing. Here we report nine novel L1 mutations in X-linked hydrocephalus and MASA-syndrome families, including the first examples of mutations affecting the fibronectin type III domains of the molecule. They are discussed in relation both to phenotypes and to the insights that they provide into L1 function.

Abnormalities, Multiple↗
PubMed1994

Genetic linkage of cone-rod retinal dystrophy to chromosome 19q and evidence for segregation distortion.

Inherited retinal dystrophies are the most common cause of childhood blindness in the developed world. Cone-rod retinal dystrophies are severe examples of this group of disorders. Analysis of a large cone-rod dystrophy pedigree suggested that inheritance within the family was influenced by meiotic drive (p = 0.008), a rare segregation distortion in human genetics. Two-point linkage analysis showed significant linkage with three markers mapping to chromosome 19q. Multipoint analysis gave a maximum lod score of 10.08 (theta = 0.05) distal to D19S47. Cone-rod dystrophy is therefore assigned to 19q13.1-q13.2 and a new candidate locus for other retinal dystrophies is identified.

Child↗
PubMed1994

Outcome of low vision aid provision: the effectiveness of a low vision clinic.

PURPOSE: Although there is an increasing need for primary low vision (LV) care, few studies have considered the success rates of optometric LV rehabilitation. We considered the objective success and perceived benefit obtained by 57 elderly LV patients. METHOD: Tests of reading speed and questionnaires were administered in the patient's home after initial and follow-up visits to a LV clinic. Additional information was taken from the patient's clinic record. RESULTS: Benefits from attending the clinic were reported by 89.5% of patients and 81% of patients were regularly using low vision aids (LVA's). There was a discrepancy between ability to read 1M print in the clinic (75% of patients) and the reported ability to read regular-sized print at home (35%). Perceived benefit from visiting the clinic was strongly associated with the ability to perform daily living tasks and to read 2M print. There was some association between perceived benefit and frequency of using the LVA's, but not with duration of use. CONCLUSION: The results encourage a change in emphasis during LV assessments from sustained reading to the ability to perform daily living activities.

Activities of Daily Living↗
PubMed1994

Mitochondrial DNA 8993 (NARP) mutation presenting with a heterogeneous phenotype including 'cerebral palsy'.

The mitochondrial DNA (mtDNA) mutation 8993 is an important cause of Leigh's encephalopathy. A family is reported where other affected members have presented with non-specific delayed development or cerebral palsy. The diagnosis should be considered not only in children with Leigh's encephalopathy, but also in those with mild neurological dysfunction (including cerebral palsy) if there is a pigmentary retinopathy or a family history of neurological or ophthalmological disease. There was some correlation in this family between the disease severity and the proportion of mutant mtDNA in the blood. This mutation appears to segregate to high levels of mutant mtDNA rapidly within pedigrees and the mother of a severely affected child has a high risk of having further children with a high proportion of mutant mtDNA and a severe phenotype.

Adolescent↗
PubMed1994

Ohdo-like blepharophimosis syndrome with distinctive facies, neonatal hypotonia, mental retardation and hypoplastic teeth.

We report four children with unusual facial features including severe blepharophimosis, ptosis, and a distinctive nose with a broad flat tip and a depressed bridge. All four patients were markedly hypotonic and had severe feeding difficulties and developmental delay. Two had congenital heart defects and all three who survived had hypoplastic teeth. Both of the male patients had cryptorchidism. These four children have a distinctive syndrome which is similar to that reported by Biesecker (J Med Genet (1991) 28: 131-134).

Abnormalities, Multiple↗