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Biomedical subjects

A E Chudley

Publications and source records attributed to A E Chudley.

At least 19 recordsLinked to original sources

Mutation analysis of the FRAS1 gene demonstrates new mutations in a propositus with Fraser syndrome.

Fraser syndrome (OMIM 219000) is a rare, autosomal recessive condition with classical features of cryptophthalmos, syndactyly, ambiguous genitalia, laryngeal, and genitourinary malformations, oral clefting and mental retardation. Mutations causing loss of function of the FRAS1 gene have been demonstrated in five patients with Fraser syndrome. However, no phenotype-genotype correlation was established and there was evidence for genetic heterogeneity. Fraser syndrome is rare and the FRAS1 gene has 75 exons, complicating mutation screening in affected patients. We have screened two patients who fulfilled the diagnostic criteria for Fraser syndrome and three patients with related phenotypes (two patients with Manitoba oculotrichoanal syndrome and one patient with unilateral cryptophthalmos and labial fusion) for mutations in FRAS1 to increase the molecular genetic data in patients with Fraser syndrome and related conditions. We report two new mutations in a patient with Fraser syndrome, a frameshift mutation and a deletion of two amino acids that we consider pathogenic as both alter the NG2-like domain of the protein. Although we are still unable to clarify a phenotype-genotype relationship in Fraser syndrome, our data add to the list of mutations associated with this syndrome.

Adolescent↗

Stem cell research: cloning, therapy and scientific fraud.

Stem cell research has generated intense excitement, awareness, and debate. Events in the 2005-2006 saw the rise and fall of a South Korean scientist who had claimed to be the first to clone a human embryonic stem cell line. From celebration of the potential use of stem cells in the treatment of human disease to disciplinary action taken against the disgraced scientists, the drama has unfolded throughout the world media. Prompted by an image of therapeutic cloning presented on a South Korean stamp, a brief review of stem cell research and the events of the Woo-suk Hwang scandal are discussed.

Animals↗

The hemoglobinopathies and malaria.

With philatelic illustrations, we review sickle cell anemia, some of the common hemoglobinopathies, and their relevance to malaria. We discuss the mechanism by which hemoglobinopathies arise, the progress made with pre-natal screening, as well as innovative therapies. We review recent developments in the pathophysiology of malaria and discuss innovations in the effort against this parasite.

Hemoglobinopathies↗

Split hand foot malformation (SHFM).

The nomenclature describing the phenotype of missing central rays in the hand and/or foot in the genetics and surgical literature is heterogeneous and confusing. Split hand/foot malformation (SHFM) is the most common term for this phenotype in the genetics community; however, other names such as the offensive 'lobster-claw malformation' and the non-specific 'ectrodactyly' are still utilized to describe this malformation. In this article, we briefly review the nomenclature associated with SHFM and its classifications.

Foot Deformities, Congenital↗

Late infantile onset krabbe disease in siblings with cortical degeneration and absence of cerebral globoid cells.

Krabbe disease, a disorder caused by the deficiency of lysosomal galactosylceramidase, is typically associated with cerebral white matter degeneration, cortical sparing, accumulation of macrophages ("globoid cells"), and ultrastructural needle-shaped inclusions. Two sisters presented with progressive neurological deterioration beginning before the age of 2.5 years. The first, who died at the age of 9 years, exhibited profound destruction of cerebral white matter with sparing of subcortical fibers but no globoid cells. The brain of the second, who died at the age of 15 years and who had a proven galactosylceramidase deficiency, exhibited white matter destruction, previously undescribed circumscribed spongiform cortical degeneration (postcentral, inferior temporal, cingulate), and cerebellar atrophy, but no globoid cells. The peripheral nerve biopsies from both girls exhibited typical needle-shaped inclusions in Schwann cells. These observations confirm the rare reports that Krabbe disease is not always associated with globoid cells in the brain. Psychosine, which accumulates in the brain, might be toxic to cortical neurons following prolonged survival. The reason for the regional susceptibility in the cerebral cortex is unknown.

Age of Onset↗

Genetic landmarks through philately--epilepsy and clinical genetic issues.

Epilepsy is a common neurologic disorder. Major advances in the understanding of the etiology and treatment have occurred. Although most cases of epilepsy do not follow a simple pattern of inheritance, recently single gene epilepsy disorders have been identified. We present some postage stamps to illustrate issues and advances in knowledge about epilepsy, as well as famous people with this disorder.

Epilepsy↗

Genetic landmarks through philately - autism spectrum disorders: a genetic update.

Autism spectrum disorders (ASD) represent a heterogeneous group of developmental disorders that present a challenge to geneticists because of their complex etiology and inheritance. This article reviews some of the advances in our understanding of causation in ASD and the role in which molecular genetic investigations have helped in unraveling the mystery of ASD. There have been few postage stamps issued relevant to ASD. Because of the need for early diagnosis and improved recognition, some countries may consider issuing stamps to highlight the importance of ASD to the population and to raise awareness and money for research funding.

Animals↗

Bowen-Conradi syndrome: a clinical and genetic study.

The purpose of the study was to delineate the anomalies and the natural life history of persons with the Bowen-Conradi syndrome [Bowen and Conradi 1976: Birth Defects: Orig Artic Ser XII(6):101-108]. We ascertained 39 cases and personally examined almost all. For those who were not seen, their clinical record were scrutinized. Pedigree analysis of all 39 was done and kinship coefficients computed. The birth prevalence was estimated to be 1/355 live births.

Craniofacial Abnormalities↗

Landmarks in genetics through philately: the tools used by dysmorphologists.

This essay liberally uses stamps from around the world to illustrate the many tools at the disposal of clinical geneticists and dysmorphologists. The tools begin with the construction of a family tree and eventually lead to the utilization of computers and the Internet as important diagnostic resources.

Anatomy↗

Landmarks in genetics through philately: Down syndrome.

Down syndrome (DS) is one of the most common chromosomal disorders; however, the molecular pathogenesis and cause remains elusive. Many advances have been made in pre-natal screening and detection, but there have been few real advances in the primary prevention or treatment of DS. DS individuals have been depicted on several philatelic materials; we present some of these stamps and philatelic covers, as well as other complementary stamps, as a means to illustrate issues relevant to this disorder.

Chromosomes, Human, Pair 21↗

Genetic landmarks through philately: Georges Marinesco (1863-1938).

Georges Marinesco was one of Romania's most eminent physicians and an accomplished neurologist. He had diverse interests in anatomy and neuropathology. He has been honored on postage stamps issued by his birth nation on several occasions. Neurologists and geneticists know of him for the rare familial degenerative neurological disorder that has been named after him, the Marinesco-Sjögren syndrome.

History, 19th Century↗

Identification of a dup(5)(p15.3) by multicolor banding.

A 7-year-old female was referred to the Genetics Clinic because of developmental delay and attentional difficulty. The patient was adopted and there was a nonspecific prenatal history of drug and alcohol abuse. The patient had clinical signs that were not compatible with typical fetal alcohol syndrome (FAS), although there was a history of alcohol exposure in utero, neurodevelopmental difficulties with learning and behavioral problems, and mild dysmorphisms. Cytogenetic analysis revealed an unbalanced female karyotype with a dup(5) containing additional chromosome 5 material at band 5p15.3. The dup(5) showed normal copy number of the cri-du-chat region on 5p15.2 using locus-specific probes D5S721 and D5S23. Multicolor banding of chromosome 5 (MetaSystems) using partial chromosome paint (pcp) probes showed a duplication of band 5p15.3. The karyotype of the patient was therefore interpreted as follows: 46,XX,add(5)mat.ish dup(5)(p15.3)(wcp5 +, D5S271 +, D5S23 +, C84C11/T3 + +, pcp5p15.3 + +). The patient's biological mother and maternal half-brother were found to carry the identical chromosome duplication. The clinical phenotype of the biological mother is complicated by a difficult lifestyle but there were apparent learning and behavioral difficulties at school. The half-brother is nondysmorphic and presents with learning problems and attention deficit disorder (ADD). His physical examination was normal. To the best of our knowledge, this is the first report of a limited duplication of 5p15.3. The clinical significance of the dup(5)(p15.3) is still uncertain but may be the basis for learning and attention difficulties.

Abnormalities, Multiple↗

Genetic landmarks through philately: Luís Morquio 1867-1935.

Morquio syndrome, also known as Mucopolysaccharidosis Type IV, is well known to pediatricians and geneticists, although it is rare. Many do not know much about the physician who first described this lysosomal disorder. In this brief review, the person and the disease are described, along with philatelic illustrations that have been issued to honor this famous Latin American medical hero.

Family Health↗

Neuronal intranuclear inclusions in a new cerebellar tremor/ataxia syndrome among fragile X carriers.

A neurological syndrome involving progressive action tremor with ataxia, cognitive decline and generalized brain atrophy has been described recently in some adult males with pre-mutation alleles of the fragile X syndrome (FXS) fragile X mental retardation gene (FMR1). Neurohistological studies have now been performed on the brains of four elderly premutation carriers, not reported previously, who displayed the neurological phenotype. Eosinophilic, intranuclear inclusions were present in both neuronal and astrocytic nuclei of the cortex in all four individuals. Systematic analysis of the brains of two of these carriers demonstrated the presence of the intranuclear inclusions throughout the cerebrum and brainstem, being most numerous in the hippocampal formation. The cerebellum displayed marked dropout of Purkinje cells, Purkinje axonal torpedoes and Bergmann gliosis. Intranuclear inclusions were absent from Purkinje cells, although they were present in a small number of neurones in the dentate nucleus and diffusely in cerebellar astrocytes. The presence of inclusions in the brains of all four FXS carriers with the neurological findings provides further support for a unique clinical entity associated with pre-mutation FMR1 alleles. The origin of the inclusions is unknown, although elevated FMR1 mRNA levels in these pre-mutation carriers may lead to the neuropathological changes.

Aged↗

Cryptic chromosome rearrangements detected by subtelomere assay in patients with mental retardation and dysmorphic features.

The regions near telomeres of human chromosomes are gene rich. Chromosome subtelomere rearrangements occur with a frequency of 7-10% in children with mild-to-moderate mental retardation (MR) and approximately 50% of cases are familial. Clinical investigation of subtelomere rearrangements is now prompted by fluorescence in situ hybridization (FISH) analysis using specific DNA probes from all relevant chromosome ends. In our study, 40 children were selected for subtelomere assay using either the Chromophore Multiprobe-T Cytocell device or the VYSIS TelVision probes. Inclusion criteria were: developmental delay or MR; a normal 550 G-band karyotype; FRAXA negative; and at least one other clinical criterion. Exclusion criteria included an identified genetic or environmental diagnosis. Of the 40 patients analysed, four (10%) were found to have subtelomere rearrangements. Three of 40 (7.5%) were found to have an unbalanced subtelomere rearrangement and one of 40 (2.5%) was found to have an apparently normal variant subtelomere deletion. The first of the three with an unbalanced karyotype was the result of a familial translocation, the second was a de novo finding, and the origin of the third could not be determined. The subtelomere FISH assay detected almost twice the frequency of unbalanced karyotypes as those detected by 550 G-banding in our cytogenetics laboratory (4.7%). In addition, subtelomere screening was eight times more likely than fragile X screening in our DNA laboratory (1%) to detect genetic abnormalities in mentally handicapped individuals. Our findings support the view that screening for subtelomere rearrangements has a greater positive yield than other commonly used genetic investigations and, if cost and resources permit, should be the next diagnostic test of choice in a child with unexplained MR/dysmorphisms and a normal 550 G-band karyotype.

Abnormalities, Multiple↗