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Biomedical subjects

B Say

Publications and source records attributed to B Say.

At least 19 recordsLinked to original sources

Huntington disease: a detective story.

As recombinant DNA diagnoses of various inherited diseases become a standard medical procedure, the practicing physician will be required to identify families at risk and counsel them (or refer them) appropriately. In many families the risk may not be immediately obvious or a reliable risk figure may appear to be unattainable. In the case presented, the patient had an apparent 50% risk for Huntington disease and all the immediate affected relatives were deceased. This relatively common scenario would generally prevent recombinant DNA diagnostic procedures from arriving at a more accurate risk estimate. Nevertheless, by recombinant DNA analysis, a risk for Huntington disease of less than 1% was obtained. Several key aspects of genetic analysis were required including extensive family histories, identification of informative markers, ordering the markers around the disease gene and appropriate statistical analyses. These discussions illustrate the power of recombinant DNA techniques to detect genetic disorders and demonstrate why they will be of increasing importance to the practicing physician.

Genetic Counseling

Spondylocostal dysplasia and neural tube defects.

Spondylocostal dysplasia (Jarcho-Levin syndrome) comprises multiple malformations of the vertebrae and ribs coupled with a characteristic clinical picture of short neck, scoliosis, short trunk, and deformity of the rib cage. We describe a patient with the syndrome who also had spina bifida and diastematomyelia. We surmise that this association is not coincidental. Additional evidence is needed to support the hypothesis that spondylocostal dysplasia and neural tube defects are aetiologically related.

Dysostoses

Split notochord syndrome with dorsal enteric fistula and sacral agenesis.

Split notochord syndrome of the lumbosacral spine in association with dorsal enteric fistula is a rare phenomenon. To date, only nine human cases have been reported in the English literature. We present another case of this type, with sacral agenesis as an additional and unique finding. Several etiological theories are discussed including the persistence of the neurenteric canal, the occurrence of an ectopic or accessory neurenteric canal, a division or local redundancy of the notochord, an entodermal-ectodermal adhesion, neural tube rupture caused by oversecretion of fluid, and failure or aberrancy of dorsal aortic distribution to the region of the neural folds resulting in prevention of timely neural tube closure.

Humans

Cloverleaf skull associated with unusual skeletal anomalies.

A male infant with cloverleaf skull and multiple other birth defects born to unrelated, healthy, young parents is presented. Radiologic findings in addition to the cloverleaf skull configuration included short, wide clavicles, winged scapulae, unusual shapes of ribs with abnormal spacing between them and with prominent costovertebral junctions, and widely separated ischia. Ulnae appeared angular with probable fusion to the midportion of the radial bones bilaterally. There was polydactyly of the hands and feet with grossly abnormal metacarpal and metatarsal bones. Skeletal maturation was normal. Computed tomography of the skull showed dilated lateral and third ventricles as well as agenesis of the corpus callosum. The mother denies any teratogenic exposure during the pregnancy. The findings in this infant do not seem to fit into any previously described syndrome.

Abnormalities, Multiple

Skeletal dysplasia in an infant with hypertelorism, hypospadias, developmental delay, and a complex chromosomal translocation.

A male infant with hypertelorism and hypospadias was found to have skeletal changes suggesting metaphyseal dysplasia. Associated findings included congenital nystagmus, hearing impairment, and a complex translocation involving the number 5, 8, and 10 chromosomes. Although some of these abnormalities may be coincidental, they might represent infrequent components of the BBB syndrome. It is just as likely, however, that the syndrome is a new one.

Bone Diseases, Developmental

Partial deletion 21: case report with biochemical studies and review.

An unbalanced translocation of a portion of the long arm of chromosome 21 to the short arm of chromosome 4 resulted in a partial deletion of chromosome 21 (pter----q21.05) and in the loss of the telomere of 4p. The phenotype of the child included asymmetrical facies, microcephaly, short stature, hypotonia, and psychomotor retardation associated with frequent infections. Normal SOD-1 activity in red blood cells and fibroblasts and normal cystathionine beta synthase activity in fibroblasts suggest that these gene loci are distal to 21q21.05.

Abnormalities, Multiple

Cytogenetic findings in acute monocytic leukemia in a renal allograft recipient.

Chromosome analysis of bone marrow cells from a patient with acute monocytic leukemia, who had had a renal transplant followed by immunosuppressive treatment 45 months prior to the onset of leukemia, showed an unusual karyotype: 48,XX,+8,+8, t(1q12----pter::11q12----qter), t(4p12----qter::6p11----pter),t(7p22----qter::12q23 ----qter?), t(1q11----qter::17p11----11qter).

Azathioprine

Microcephaly, short stature, and developmental delay associated with a chemotactic defect and transient hypogammaglobulinaemia in two brothers.

Two brothers presented with unusual facial features, microcephaly, developmental delay, and severe postnatal growth retardation. They both developed eczema in infancy and have had recurrent infections. Additional physical findings in both boys included hypogonadism, flexion contractures, hypoplastic patellae, and scoliosis. Their facial similarity was striking with sloping foreheads, beaked noses, large, protruding ears, and micrognathia. Low levels of serum gammaglobulins and defective chemotaxis were present in both boys in infancy. The hypogammaglobulinaemia was transient and improved, reaching normal levels by 3 1/2 years and 15 months, respectively. Defective chemotaxis and recurrent infections have persisted to the present. Both parents were normal. The mode of inheritance was not clear, as both X linked and autosomal recessive patterns were possible. Although patients with congenital malformations who also had immunodeficiency have previously been reported, immune system abnormalities, especially those of a transient nature, may frequently go unrecognised.

Abnormalities, Multiple

A homozygote for pericentric inversion of chromosome 4.

A child with developmental and language delay was found to be homozygous for a pericentric inversion of chromosome 4 (inv(4) (p15 X 2q12)). Her normal mother and aunt are inversion heterozygotes. It is suggested that the phenotypic abnormalities may have resulted from damage at chromosomal breakpoints or from a position effect which is expressed only in homozygous form.

Abnormalities, Multiple