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Biomedical subjects

N J Carpenter

Publications and source records attributed to N J Carpenter.

At least 55 records · Page 3Linked to original sources
PubMed1981

An infant with ring 17 chromosome and unusual dermatoglyphs: a new syndrome?

A case of ring 17 chromosome in a 5-month-old male infant is investigated and compared with five previously reported cases. The findings commonly observed in these patients include mental and motor retardation, seizures, short stature, muscular hypotonia, and microcephaly among others. Dermatoglyphic studies showed an increased number of ulnar loops. More interestingly, bilateral transverse hypothenar creases were noted. Two of the reported cases also had unspecified genital abnormalities. The variation in clinical findings among these patients may be explained by a difference in the breakpoints on chromosome 17.

Abnormalities, Multiple↗
PubMed1980

Gonadal dysgenesis in a patient with an X;3 translocation: case report and review.

A patient with primary amenorrhoea and absence of secondary sex characteristics was found to have a balanced X;3 translocation. This phenotype is reported in approximately one-third of the balanced X;autosome translocation cases. The normal X chromosome is inactive in the present case which is in agreement with most of the similar cases. A review of the 66 balanced X;autosome translocations reported to date is presented.

Adolescent↗
PubMed1980

Agenesis of the lung associated with a chromosome abnormality (46,XX,2p+).

We describe a patient with agenesis of the left lung who also had a chromosome abnormality, probably representing a duplication of the distal part of the upper arm of chromosome 2. In addition to this finding, the existence of familial cases of lung agenesis indicate that further studies are required for better understanding of the genetic aspects of this condition.

Chromosome Aberrations↗
PubMed1979

Down syndrome due to 21;21 translocation in a male twin.

A spontaneous 21;21 translocation resulting in features consistent with Down syndrome is reported in the first born of male fraternal twins. No history of twinning or chromosomal abnormalities in the family was noted. Any association between dizygous twinning and Down syndrome due to de novo translocation remains speculative until a sufficient pool of published data is available from study of such families.

Chromosomes, Human, 21-22 and Y↗
PubMed1977

Chromosome variants in children with psychiatric disorders.

The authors studied the frequency of chromosome variants in 48 hospitalized children with psychiatric diagnoses (study group) in comparison with 10 hospitalized children with nonpsychiatric diagnoses (control group) and the results of three surveys of newborn children. They found that the frequency of variants in their study group was elevated in comparison with their control group and with the newborn surveys.

Adolescent↗
PubMed1973

Thymidylate synthetase in mutants of Drosophila melanogaster.

Thymidylate synthetase has been examined with respect to the normal pattern of activity throughout the development of the Oregon-R strain of Drosophila melanogaster. Large amounts of the enzyme are present in both the unfertilized and the fertilized eggs. A comparison of the ovarian thymidylate synthetase activity of the Oregon-R strain and the female sterility mutants, fs(2)B, fu, and fs(1)N, indicates variations in the activity of this enzyme in each strain. At four days of age, the ovarian-specific activity of the female sterility mutants is comparable to or less than that of the Oregon-R strain, but it is reduced at fifteen days of age. The enzyme activity per ovary is low in the fs(2)B strain but is similar in the Oregon-R, fu, and fs(1)N strains. When expressed as activity per organism, thymidylate synthetase declines after six to eight hours of development until the minimal level is reached in the late embryonic stage. Enzyme activity rises throughout the larval instars, reaching a maximum immediately after puparium formation. The activity decreases during pupation, but rises again during the first four days of adult life.

Aging↗
PubMedDate not supplied

Gonadal function in men with the Martin-Bell (fragile-X) syndrome.

We evaluated testicular function in 15 men with the Martin-Bell (fragile-X) mental retardation syndrome. Macro-orchidism was present in all subjects. Their mean serum LH and FSH levels and plasma testosterone and dihydrotestosterone levels were normal. The mean plasma levels of androstenedione, 17-hydroxyprogesterone, and progesterone were slightly elevated above the normal range, whereas the plasma levels of dehydroepiandrosterone and dehydroepiandrosterone-sulfate were normal. The response in the levels of plasma testosterone following a 5 day period of hCG stimulation was normal in 8 subjects and there was no abnormal accumulation of androgen precursors. The level of 5 alpha-reductase activity and androgen receptor binding was normal in genital skin fibroblasts derived from 3 of these patients. The response of gonadotropin secretion to GnRH stimulation was normal in the 8 men who were tested. Therefore, our data are consistent with the hypothesis that testicular enlargement in men with the Martin-Bell syndrome is not mediated by hormonal factors.

Adolescent↗
PubMedDate not supplied

Photoanthropometric analysis of individuals with the fragile X syndrome.

A photoanthropometric method, which enables an objective description of facial structures, was used to examine 31 boys with the fragile X or Martin-Bell syndrome below the age of 12 years. The age range was 1.5 to 12 years with an average age of 6.5 years. Facial parameters were measured from strict frontal and profile photographs of fra(X) syndrome boys and compared with other facial measurements from the same face (e.g. mouth width vs. bizygomatic diameter). We studied 18 photoanthropometric facial parameters following the protocol established by Stengel-Rutkowski et al [1984]. Fourteen indices were calculated and compared with photoanthropometric index standards for age, established from normal children between 0 and 12 years [Stengel-Rutkowski et al, 1984]. Two of the fourteen craniofacial indices, broad palpebral fissures and decreased inner canthal distance, were significantly abnormal.

Anthropometry↗
PubMedDate not supplied

Unique X-linked mental retardation syndrome with fingertip arches and contractures linked to Xq21.31.

We studied 10 members of a 4 generation Missouri kindred with a dominant mental retardation syndrome with increasing severity in males. The 21 year-old propositus presented with severe mental retardation, microcephaly, asymmetric face, exotropia, hypogonadism, joint hypermobility, rocker bottom feet, and 10 low digital arches. Two brothers and a male cousin had similar features. The mother, sister, niece, maternal aunt, female cousin, and grandmother were examined and each had 8 to 10 low digital arches. Five of the women had exotropia and one had pes cavus feet. Chromosome analysis for fragile X in multiple relatives was normal. To determine the likelihood that this was an X-linked syndrome. DNA from relatives was hybridized to probes which detect 13 different loci spanning the X-chromosome. A peak LOD score of 2.78 at theta equal to 0.0 was calculated for the syndrome locus and DXYS1 (pDP34). The more distal Xq loci showed increasing recombination with the syndrome locus. These results are consistent with location for this syndrome near Xq21.31, the chromosomal locus for DXYSI.

Abnormalities, Multiple↗
PubMedDate not supplied

Martin-Bell syndrome segregating in a large kindred with normal transmitting males: clinical, cytogenetic, and linkage study.

We report on a large kindred with 10 mentally retarded, fra(X) positive males and 2 normal transmitting males. Clinical findings include variable degrees of facial anomalies, macroorchidism, behavioral characteristics, and cognitive deficiencies. The affected grandsons were fra(X) positive while their obligate carrier mothers and transmitting grandfathers were fra(X) negative. DNA-restriction fragment length polymorphism (RFLP) linkage study was undertaken to find informative markers to identify heterozygotes or hemizygotes. The problems encountered in genetic counselling, by the absence of established criteria for diagnosis, are discussed.

Adolescent↗
PubMedDate not supplied

DNA linkage analysis of 26 families with fragile X syndrome.

Linkage data using the markers F9 (factor IX), DXS105 (cX55.7), DXS98 (4D-8), DXS52 (St14), DXS15 (DX13), and DXS134 (cpX67) are presented from 26 pedigrees segregating with fragile X (fra[X]) syndrome. Cytogenetic and DNA data were combined in 2-point linkage analysis for the estimation of lod scores and carrier probabilities in potential carriers. Recombination fractions (theta) corresponding to the maximum lod scores (Z) were obtained for F9 (Z = 2.78, theta = 0.15), DXS105 (Z = 1.72, theta = 14), DXS98 (Z = 3.74, theta = 0.00), DXS52 (Z = 3.53, theta = 0.17), DXS15 (Z = 4.03, theta = 0.11), and DXS134 (Z = 2.12, theta = 0.16) and for the fragile X locus (FRAXA). Recombination fractions between marker loci in the families are also presented. Discordance between the results of cytogenetic and DNA analyses in 2 potential carrier females was investigated by reexamination of the fragile site expression and was concluded to be due to the expression of the common fragile site at Xq27.2.

DNA↗
PubMedDate not supplied

Linkage relationships between DXS105, DXS98, and other polymorphic DNA markers flanking the fragile X locus.

We report on linkage data between DXS105, DXS98, the locus for the fragile X syndrome (FRAXA), and 3 other polymorphic loci that flank the FRAXA locus. An analysis was undertaken to determine the relative positions of DXS105 and DXS98 and to test the assignment of DXS105 to a location proximal and closely linked to FRAXA. In this study of fragile X fra(X) syndrome families, the DXS105 locus was calculated to be proximal to FRAXA with a maximum lod score of 10.36 at theta = 0.08. DXS105 was also shown to be closely linked to the gene for factor IX (F9)(Z = 11.84 at theta = 0.08) and to DXS98 (Z = 4.91 at theta = 0.04). The order of the loci proximal to FRAXA is most likely centromere-factor IX-DXS105-DXS98-FRAXA-telomere. The use of DXS105 and DXS98 in clinical investigations should significantly increase the accuracy of risk assessment in informative fragile X families.

Chromosome Mapping↗