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Biomedical subjects

D D Weaver

Publications and source records attributed to D D Weaver.

At least 73 records · Page 4Linked to original sources
PubMed1984

Terminal and interstitial deletions of the long arm of chromosome 7: a review with five new cases.

Sixteen cases of terminal deletions and 17 cases of interstitial deletions of the long arm of chromosome 7 have been reported to date. We present two new cases of the former and three of the latter. The somatic changes in these patients are tabulated and an update on the anomalies associated with the various cytogenetic entities is presented. Changes found in over one-third of patients with 7q terminal deletion syndrome include: developmental delay, pre- and postnatal growth retardation, generalized hypotonia, abnormal electroencephalograms with or without seizures, feeding problems in infancy, microcephaly, prominent forehead, ocular hypertelorism, eye defects, broad nasal bridge, bulbous nasal tip, auricular malformations, micrognathia, chest abnormalities, genital malformations in males, and abnormal palmar and plantar creases. Evidence for the localization of the Kidd blood group gene on chromosome 7 distal to band q32, as suggested by previous reports, is reviewed; we conclude that the evidence does not warrant placement of the gene in this region of the genome.

Abnormalities, Multiple↗
PubMed1984

In utero brain destruction resulting in collapse of the fetal skull, microcephaly, scalp rugae, and neurologic impairment: the fetal brain disruption sequence.

Three infants are reported with a recognizable pattern of defects consisting of severe microcephaly, overlapping sutures, prominence of the occipital bone, and scalp rugae. This condition, which we think represents microhydranencephaly, appears to be produced by partial brain destruction during the second or third trimester, diminution in intracranial hydrostatic pressure, and subsequent collapse of the fetal skull. Several different causes for this condition have been suggested including partial disruption of the blood supply to the brain and prenatal viral infection.

Adult↗
PubMed1984

Acrofacial dysostosis with severe facial clefting and limb reduction.

We describe two unrelated patients with a severe form of acrofacial dysostosis. Facial defects in both include coloboma of the lids, micrognathia, lateral oral clefting, palatal clefting, and severe auricular anomalies, with one showing bilateral cleft lip and right oblique facial clefting as well. Both have absent forearms and thumbs. Lower limbs were severely reduced in both infants with the feet attached either to the femur or directly to the trunk. Parental consanguinity was present in one case. The condition in these two infants appears to represent either a severe form of Nager acrofacial dysostosis or a new type of acrofacial dysostosis.

Abnormalities, Multiple↗
PubMed1984

Ethical considerations in medical genetics--the prenatal diagnosis of hemophilia B.

A couple is presented who underwent prenatal counseling and amniocentesis for sex determination because the wife was an obligate carrier of hemophilia B. Although the fetus was determined to be male, the parents elected not to have further testing to determine if he had hemophilia or not. The difficulties in the in utero diagnosis of hemophilia B are presented and discussed. In addition, the moral reasoning and decision-making process that this couple went through regarding the decision not to have further fetal testing and to continue the pregnancy is presented and analyzed. These moral decisions appear to be based on family and personal ties, and bonding to the fetus after perception of fetal movement. They combine considerations of the duties and rights involved in such situations, and attend to the anticipated consequences as well.

Adult↗
PubMed1984

Computed tomographic findings in metastatic dural carcinomatosis.

A case is presented of metastatic dural carcinomatosis associated with a thickened subdural membrane similar to those found in association with posttraumatic chronic subdural hematomas. In this case burr-hole drainage was attempted as a result of findings on computed tomography scanning that suggested a right frontal chronic subdural hematoma. However, no chronic subdural hematoma or effusion was found. The pathology, radiographic findings, and clinical features of this phenomenon are discussed.

Aged↗
PubMed1984

Endocrine and genetic characterization of cousins with male pseudohermaphroditism: evidence that the Lubs phenotype can result from a mutation that alters the structure of the androgen receptor.

Impaired virilization of genetic males with testes (male pseudohermaphroditism) can result either from deficiency in androgen production or defects in androgen action, the latter most commonly involving an abnormal androgen receptor. We report here two maternal cousins with male pseudohermaphroditism and clinical features characteristic of the Lubs phenotype, namely apparent females with sufficient fusion of the labioscrotal folds so that a single urogenital sinus orifice is present. Testosterone levels in these genetic males rose appropriately after administration of human chorionic gonadotropin. The amount (maximal binding capacity of 24 to 30 fmol/mg protein) and hormone binding affinity (half-maximal saturation of 0.2 nM) of the androgen receptor in cultured skin fibroblasts was normal, but the receptor was qualitatively abnormal as evidenced by instability on sucrose density gradient centrifugation. The pattern of inheritance in this family is compatible with X-linkage. These findings, together with previous studies, indicate that the spectrum of abnormalities that result from defects of the androgen receptor in genetic men can encompass the entire spectrum between male and female phenotypes.

Chorionic Gonadotropin↗
PubMed1984

Type IX Ehlers-Danlos syndrome. A new variant with pathognomonic radiographic features.

The authors describe 7 male patients from two unrelated families who presented with what appears to be a heretofore undiagnosed X-linked variant of Ehlers-Danlos syndrome. Unlike the eight previously reported types, this variant is manifested by specific skeletal abnormalities, including occipital exostoses, widening and bowing of multiple long bones at tendinous and ligamentous insertion sites, and deformed clavicles. Major clinical complications include genitourinary problems, chronic diarrhea with malabsorption, and/or syncopal episodes. Laboratory tests suggest that this variant may represent the true lysyl-oxidase-deficient form of Ehlers-Danlos syndrome.

Adolescent↗
PubMed1984

A mutation that causes lability of the androgen receptor under conditions that normally promote transformation to the DNA-binding state.

Dihydrotestosterone-receptor complexes formed in human fibroblast cytosol prepared at 0 degrees C in the presence of sodium molybdate can be readily transformed to the DNA-binding state by heating at 25 degrees C. Under these conditions 50-70% of dihydrotestosterone-receptor complexes bind to DNA. We describe here studies of the transformation process in cytosols derived from normal cells and from fibroblasts propagated from subjects with syndromes of androgen resistance. In contrast to the situation with dihydrotestosterone, normal testosterone-receptor complexes are unstable under in vitro transforming conditions. Although equal amounts of hormone-receptor complex are formed at 0 degrees C, only 15% of testosterone-receptor complexes remain stable and acquire DNA-binding capacity after warming. This instability is not reversible upon lowering the temperature and is corrected by low concentrations (0.25 microM) of the protease inhibitor leupeptin. We have also identified two cousins with androgen resistance whose androgen-receptor complexes exhibit similar in vitro transformation lability with both dihydrotestosterone and testosterone. Phenotypic evidence in these subjects indicates that dihydrotestosterone-mediated processes are more completely impaired than are testosterone-mediated events. These findings suggest that dihydrotestosterone may amplify the androgenic signal at its targets not only by its higher affinity for the receptor but also by its more efficient conversion to the DNA-binding state and that such amplification may be less critical in target tissues in which testosterone suffices for androgenic effect. This offers one possible explanation of how a mutation that affects a single receptor protein may differentially impair the actions of two binding ligands of the receptor.

Child, Preschool↗
PubMed1983

Part II. Amyoplasia: twinning in amyoplasia--a specific type of arthrogryposis with an apparent excess of discordantly affected identical twins.

We report on 11 cases of amyoplasia in one of identical twins. In total, 135 patients with amyoplasia were ascertained from a study of 350 patients with multiple congenital joint contractures (arthrogryposis). These 11 cases of identical twins with amyoplasia represent 8% of our patients with amyoplasia. At least 18 sets of twins with congenital contractures have been reported previously. However, only four of these appear to involve identical twins discordant for amyoplasia. Thus, 15 cases in which only one of identical twins are affected with amyoplasia have been identified.

Adolescent↗
PubMed1983

Hirschsprung disease: etiologic implications of unsuccessful prenatal diagnosis.

We describe an infant with Hirschsprung disease (congenital aganglionosis of the intestine) involving the colon and terminal ileum. Midtrimester prenatal diagnosis of this disorder in this infant was attempted utilizing amniotic fluid disaccharidase analyses, ultrasound, and amniography. Decreased disaccharidase activities in amniotic fluid have been reported previously in association with other forms of intestinal obstruction. At 15 weeks' gestation, normal amniotic fluid disaccharidase levels were obtained. Serial ultrasound evaluations did not indicate any pathology, and the results from amniography were inconclusive. The implication of the normal disaccharidase values is that Hirschsprung disease may in some cases result from degeneration of intestinal ganglia after 16 weeks' gestation rather than from faulty migration of neural crest cells. The inheritance of Hirschsprung disease is generally consistent with sex-modified multifactorial inheritance with a lower threshold of expression in males. The case we report has a family history of three affected first- and second-degree relatives. Autosomal dominance with variable expressivity is a possible explanation in this family.

Amniotic Fluid↗
PubMed1983

Dicentric chromosome 13 and centromere inactivation.

The karyotype of a child with dysmorphic findings suggestive of both trisomy 13 and the 13q--syndrome was found to have cells with one of two different dicentric chromosomes: one bearing a duplication of chromosome 13q [46,XX,-13, + psu dic (13)t(13;13)(pter leads to cen leads to q34::q34 leads to pter)] and the other a deletion of 13q [46,XX,-13, + psu dic (13)t(13;13)(pter leads to cen leads to q22::q11 leads to pter]. Longitudinal cytogenetic studies in leukocytes demonstrated a loss of those cells possessing the small dicentric [psu dic(13)(q22;q11)], whereas fibroblasts from two separate skin biopsies contained only this marker. Q-band polymorphisms indicated that both dicentrics were of paternal origin, with the smaller dicentric derived from the larger via the bridge-breakage-fusion cycle. The presence of two active centromeres could not be confirmed in either dicentric.

Centromere↗
PubMed1983

Epidermolysis bullosa--pyloric atresia. An autosomal recessive syndrome.

A sister and brother each had epidermolysis bullosa and pyloric atresia at birth. Both died in early infancy of complications related to epidermolysis bullosa. Electron microscopic studies of skin biopsy specimens disclosed findings consistent with a diagnosis of epidermolysis bullosa letalis. The existence of epidermolysis bullosa-pyloric atresia syndrome as a distinct clinical entity with autosomal recessive inheritance is supported by the findings in these patients.

Epidermolysis Bullosa↗
PubMed1982

Pericentric X inversion in dizygotic twins who differ in X chromosome inactivation and menstrual cycle function.

A 21-year-old female dizygotic twin was referred for cytogenetic evaluation because of mild mental retardation. Significant history, clinical, and physical findings included irregular menses, mildly coarse facies, and microcornea. Chromosome analysis revealed a pericentric inversion of the X chromosome, 46, X, inv (X)(p11;q22). Her twin who is phenotypically normal was also found to carry the same inversion. The twins differ significantly in X chromosome inactivation and menstrual cycle function.

Adult↗
PubMed1982

Hyperexplexia: an inherited disorder of the startle response.

A family is presented with hyperexplexia, a rare autosomal dominant neurological disorder. Affected individuals manifest flexor hypertonia and hypokinesia during infancy. Later and throughout life, the condition is characterized by exaggerated involuntary myoclonic startle reactions, which on occasion result in falling. There are also marked nocturnal myoclonic jerks. Many family members have had congenital hip dislocations and inguinal hernias. Pre- and postnatal hypertonia is proposed as the cause for these problems. The nature and location of central nervous system dysfunction in hyperexplexia was investigated using electroencephalographic and brainstem-evoked response techniques. A dysfunction of cortical inhibition of the brainstem-mediated startle response is discussed as a possible pathogenic mechanism. Accurate diagnosis of this disorder is important in order to provide appropriate counseling and to initiate effective treatment.

Adolescent↗