Search PubMed⌕ Search

Biomedical subjects

S J Funderburk

Publications and source records attributed to S J Funderburk.

At least 19 recordsLinked to original sources
PubMed1987

Structural organization and DNA methylation patterning within the mouse L1 family.

We have studied stable differences in patterns of DNA methylation seen in the repeated sequences of mouse cells. A cloned 1330-base pair fragment of mouse repetitive DNA (pFS-13) was used as a probe in Southern blotting experiments. Mouse spleen and L1210 lymphoma DNA appeared to be normally methylated at HpaII sites probed by this sequence. Friend erythroleukemia cell, and Sp2 cell DNA both showed an abnormal banding pattern in HpaII digests. Hybridization in situ to metaphase chromosomes showed that probed sequences were broadly interspersed along the arms of each mouse chromosome. The DNA sequence of the 1330-base pair insert in the clone was determined; a copy of the R sequence of L1 was found at its 5' end. Walking experiments using M13 subclones from pFS-13 permitted the construction of a map for d(pCCGG) sites at the 3' end of the mouse L1 family. The unmethylated d(pCCGG) sites in Sp2 and Friend cells could then be assigned to polymorphic-repeated sequence groups within L1, homologous to the region spanned by BAM5 and R. Since there are several thousand copies of each of the fragments seen in autoradiographs, these sequences must possess a common methylation state at many genomic locations. Concerted (nonrandom) hypomethylation of certain subfamilies of L1 appears to be a stable characteristic of several cell lineages. These findings suggest that certain L1 families possess commonalities that permit and perhaps require differential DNA methylation in established cell lineages.

Animals↗
PubMed1987

Primate evolution of a dispersed human repetitive DNA sequence.

A dispersed middle repetitive DNA sequence isolated originally from human chromosome 12 did not show homology with rodent DNA under standard conditions of Southern DNA blot analysis. The evolutionary relationship of this human repetitive DNA to that of other primates was investigated using three hybridization methods: DNA dot blot, Southern DNA blot analysis, and chromosome in situ hybridization. Homology with the human repetitive DNA was found throughout the suborder Anthropoidea, in fourteen ape and New and Old World monkey species. In addition, the human pattern of hybridization to noncentromeric regions of all chromosomes was seen. No hybridization by any of the three techniques was found in five species of the suborder Prosimii. The phenomenon of marked differences in sequence homology and copy number of dispersed repetitive DNA from closely related species has been observed in protozoans (Plasmodia), Drosophila, sea urchins, mice and the great apes (Hominoidea). We report here a similar phenomenon that may have occurred at an early stage in primate evolution.

Animals↗
PubMed1979

Prominent acrocentric chromosome satellites in child patients with mental retardation or psychiatric disorders; no IQ-satellite size correlation.

Child patients with mental retardation or psychiatric disorders were selected for the presence of prominent acrocentric chromosome satellites and highest or lowest IQ scores. No correlation was found between IQ scores, of which eleven were below IQ 54 and 16 above IQ 68, and the length of acrocentric short arm, satellite, stalk, or short arm material below the stalk. Conventional staining, quinacrine fluorescence, C banding and ammoniacal silver staining revealed the apparent same acrocentric short arm variation between patient and one parent in eight families studied. These findings suggest that the satellite variants were truly normal variants and not etiologically related to the developmental disorders seen in the patients.

Child↗
PubMed1979

Phenotypic variation in two patients with a ring chromosome 22.

Two severely mentally retarded patients with a ring chromosome 22 presented with disparate phenotypes: one patient manifested only minimal dysmorphic features, whereas the other had a distinctive pattern of anomalies consisting of an abnormal skull configuration with mild maxillary hypoplasia, a large nose, thick full lips, a protruding tongue, lymphedema, hypotonia and an unsteady gait. The findings in these and previously reported patients indicate that a ring chromosome 22 is usually associated with moderate to severe mental retardation, with a range of dysplastic features from mild and nonspecific to more marked and distinctive.

Abnormalities, Multiple↗
PubMed1979

The 9p-syndrome.

A 13-year-old boy with 9p- (p22 leads to pter) is reported. He had many features in common with previous 9p- cases, as well as several distinctive features including polydactyly and precocious puberty. Cytogenetic studies revealed a de novo deletion distal to ban 9p22, which was the reported site of chromosome break in 9 of the 10 previous 9p- cases. Evaluation of the human GALT enzyme suggests that its locus is not on the deleted segment.

Abnormalities, Multiple↗
PubMed1979

18p--syndrome resulting from translocation (13a;18q) in a mildly affected adult male.

The patient was a 27-year-old male with short stature, borderline mental deficiency, strabismus, and a short fourth metacarpal. His karyotype showed deletion of the short arm of a chromosome 18 as the result of de novo fusion centric translocation between chromosomes 13 and 18 (45,XY, --13, --18, +t(13;18) (13qter yields cen yields 18qter).

Adult↗
PubMed1979

Regional localization of human gene loci on chromosome 9: studies of somatic cell hybrids containing human translocations.

Somatic cell hybrids were derived from the fusion of (1) Chinese hamster cells deficient in hypoxanthine guanine phosphoribosyltransferase (HPRT) and human cells carrying an X/9 translocation and (2) Chinese hamster cells deficient in thymidine kinase (TK) and human cells carrying a 17/9 translocation. Several independent primary hybrid clones from these two series of cell hybrids were analyzed cytogenitically for human chromosome content and electrophoretically for the expression of human markers known to be on human chromosome 9. The results allow the assignment of the loci for the enzymes galactose-1-phosphate uridyltransferase (GALT), soluble aconitase (ACONs), and adenylate kinase-3 (AK3) to the short arm of chromosome 9 (p11 to pter) and the locus for the enzyme adenylate kinase-1 (AK1) to the distal end of the long arm of human chromosome 9 (hand q34). Earlier family studies have shown that the locus for AK1 is closely linked to the ABO blood group locus and to the locus of the nail-patella (Np) syndrome. Thus the regional localization of AK1 locus permits the localization of the AK1-Np-ABO linkage group.

Aconitate Hydratase↗
PubMed1978

Chromosome 7 short-arm interstitial deletion (p14).

A 13-year-old girl presented with microcephaly, short and broad neck, low posterior hairline, congenital heart disease, limitation of joint movement, and mild mental retardation. Chromosomal analysis showed interstitial deletion of band p14 of the short arm of chromosome 7. The patient's physical and cytogenetic findings are compared with those of five other patients with 7p- deletions.

Adolescent↗
PubMed1978

Minor chromosome variants in child psychiatric patients.

The frequency of minor chromosome variants, as detected by conventional chromosome analysis, was examined among 1,289 child psychiatric patients, of whom one-fourth had only behavioral problems and three-fourths had congenital abnormalities and more severe mental disorders. There was no more than random association between prominent satellites, prominent secondary constrictions or a long Y chromosome, and congenital abnormalities or more severe mental disorders. The frequencies of these chromosome variants were affected by race as has been shown in previous studies. These findings do not support the evidence for a developmental effect of minor variants in man.

Chromosome Aberrations↗
PubMed1978

The G and BBB syndromes: case presentations, genetics, and nosology.

Hypertelorism and hypospadias are described in four unrelated boys; bilateral cleft lip and cleft palate were also present in two of the boys and mild mental retardation in another. These features are compatible with both the G and BBB syndromes. When present, laryngotracheoesophageal anomalies or respiratory and swallowing difficulties are characteristic features of the G syndrome; otherwise facial features may be useful in distinguishing the G and BBB syndromes. Cases 1 and 2 had anteverted nares and a broad and flat nasal bridge, and Case 1 had shortened palpebral fissures, all consistent with the G syndrome. In contrast, Cases 3 and 4 had a high and broad nasal bridge as previously described in the BBB syndrome. The father of Case 1 had mild hypertelorism and first-degree hypospadias, demonstrating autosomal dominant inheritance in the G syndrome. The mothers of Cases 2, 3, and 4 all had mild hypertelorism consistent with autosomal dominant inheritance and partial male-sex limitation, as previously proposed for both the G and BBB syndromes.

Abnormalities, Multiple↗
PubMed1978

Report of a trisomy 8p infant with carrier father.

This report describes an infant with fatal congenital heart disease, cleft palate, brain malformations, and trisomy 8p resultant from the paternal balanced reciprocal translocation, rcp(8;15) (p11;p11). Review of six previously reported trisomy 8p patients (resultant from parental balanced translocation in each instance) revealed severe mental retardation in five, short stature in all, and a variety of brain, skeletal, and cardiac defects. The features of the seven trisomy 8p patients reviewed here are not sufficiently similar to suggest a distinct dysmorphic syndrome. In addition the features differ from those in the trisomy 8 mosaicism syndrome, in which the mental retardation and malformations are generally less severe.

Abnormalities, Multiple↗
PubMed1977

18p--syndrome resulting from 14q/18q 'dicentric' fusion translocation.

A child with nasal hypoplasia, growth and developmental delay, and 18p--due to 14q/18q apparent dicentric fusion is reported. Review of ten previously reported patients with 18p--due to fusion translocations involving the long arm of chromosome 18 reveals clinical features ranging from arrhinencephaly to minimal dysmorphic changes and mild retardation. This spectrum of clinical expression is similar to that seen in patients with partial 18p deletions. Since the same range of clinical features is observed whether there is partial or apparent total deletion of 18p, it is suggested that only a distal segment of the short arm of chromosome 18 may be etiologically related to the clinical phenotype in the 18p--syndrome.

Child, Preschool↗
PubMed1977

Mental retardation associated with "balanced" chromosome rearrangements.

Balanced chromosome rearrangements were found in seven of 455 retarded children vs. four of 1,679 nonretarded, psychiatric children (P less than .05). The combined incidence of non-Robertsonian balanced rearrangements from this and reported surveys of the mentally retarded was five times greater than that from newborn surveys, whereas Robertsonian translocations were not increased among the retarded. The combined data show an increase in de novo rather than familial rearrangements among the retarded; the increase in de novo rearrangements is specifically for non-Robertsonian translocation.

Adolescent↗
PubMed1976

Suboptimal pregnancy outcome among women with prior abortions and premature births.

Data from 25,958 consecutive UCLA deliveries were analyzed to determine the effect of prior abortions and premature births on current pregnancy outcome. Perinatal death rate, combining stillbirths and neonatal deaths, increased more than threefold among women with at least one prior premature in birth and at least one prior abortion and approached 18 per cent of current deliveries when there were three or more prior premature births. Abnormal live births, defined as infants with either birth weight under 2,501 grams, gestational age less than 37 weeks, or congenital anomalies, significantly increased as the number of prior abortions and premature births increased, each in a range of 0 through 3 or more. For example, among women with at least three prior premature births, there were greater than 50 per cent abnormal live births. The risk was mostly that of low birth weight and low gestational age, although there was a slight increase in congenital anomalies. The risk was reduced considerably when there were previous term births and was influenced variably by race, clinic classification, maternal illness, and prior pregnancy complications. This empirical data on pregnancy outcome should be useful in reproductive counseling among women with pregnancy losses and premature births.

Abortion, Spontaneous↗