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L J Raffel

Publications and source records attributed to L J Raffel.

34 records · Page 2Linked to original sources
PubMed1992

Prenatal detection of 45,X/46,XX/47,XXX mosaicism through amniocentesis: mosaicism confirmed in cord blood, amnion, and chorion.

Sex chromosome mosaicism in amniotic fluid cells poses a serious dilemma in prenatal diagnosis. Chromosome analysis of 56 primary clones of amniocytes revealed three distinct cell lines. Nine cells (16.1 per cent) demonstrated a 45,X karyotype, 11 cells (19.6 per cent) a 47,XXX karyotype, and the remaining 36 cells (64.3 per cent) had a modal number of 46 chromosomes (46,XX). Cytogenetic evaluation of 100 cells from cord blood, amnion, and chorion following delivery confirmed this triple mosaicism. However, the distribution of the three karyotypes in the pre- and postnatal samples was not found in the same proportions. The cord blood had the most similar frequency to that of the amniotic fluid sample, while the chorion had a significantly increased frequency of 47,XXX cells (41 per cent) and a decreased frequency of 45,X cells (2 per cent). Physical examination of the infant at birth revealed no discernible phenotypic abnormalities. Parental karyotypes were normal. This case highlights the difficulty in determining whether a prenatally detected abnormality will be associated with postnatal phenotypic deviation.

Adult↗
PubMed1992

An unusual mosaic karyotype detected through prenatal diagnosis with duplication of 1q and 19p and associated teratoma development.

A 40-year-old white woman underwent amniocentesis for advanced maternal age at 15.4 weeks gestation. Fetal chromosome analysis demonstrated two distinct cell lines: [46,XX,t(1;19)(p11;p11)]--10%; and [47,XX,t(1;19)(p11;p11) + der(1)t(1;19)(p11;q11)]--90%. The latter karyotype was trisomic for both 1q and 19p. The mother carried the balanced translocation; the father had a normal karyotype. Amniotic fluid alpha-fetoprotein level was elevated and an acetylcholinesterase band was detected. Level II ultrasonography at 17 and 24 weeks revealed several abnormalities, including a large facial cleft and a probable facial teratoma and intracranial tumor. Autopsy following pregnancy termination confirmed the presence of both. Chromosome evaluation of 172 metaphases of both the epignathus and the intracranial teratoma demonstrated a predominance of the cell line with 47 chromosomes (166/172 = 96.5%), while from nonteratoma tissue (lung, liver, skin, and brain) only the balanced karyotype was detected. These observations suggest that the chromosomal imbalance is instrumental in the etiology of the teratoma.

Abnormalities, Multiple↗
PubMed1992

The aggregation of the 5' insulin gene polymorphism in insulin dependent (type I) diabetes mellitus families.

Population studies have suggested an increased frequency of small DNA insertions (class I alleles) 5' to the insulin gene in insulin dependent (type I) diabetes mellitus (IDDM). The present study examined this relationship within families. Forty-one families with at least one diabetic offspring were studied. Analysis of the insulin gene polymorphism was performed by digestion of DNA with Bg1I, SstI, RsaI, or PvuII and hybridisation with an insulin gene probe or polymorphic region specific probes. An increased frequency of class I alleles was found among the parents of diabetics (p = 0.02), as well as a trend towards increased frequency of parents homozygous for class I alleles and matings of two homozygous subjects. This increased homozygosity for class I alleles was present in non-diabetic sibs as well (p = 0.01). These results show that ascertainment through an offspring with IDDM selects for families with high frequencies of homozygosity for the class I allele and thus suggests that the insulin gene polymorphism is indeed providing part of the genetic predisposition to IDDM. When the major portion of genetic predisposition is provided by other genes (estimates are that HLA accounts for 30 to 70% in IDDM), identification of additional susceptibility genes becomes difficult. Even when formal linkage analysis is uninformative, our studies indicate that analysis for aggregation of specific alleles within families is a useful approach to this problem.

Diabetes Mellitus, Type 1↗
PubMed1991

Prenatal ascertainment of an inherited dup(18p) associated with an apparently normal phenotype.

Direct two-generation transmission of an unbalanced 18p+ chromosome was discovered after amniocentesis. Neither the mother nor the child exhibited apparent physical malformations or mental impairment. Banding analysis suggested a complete 18p duplication. Molecular studies verified the 18p origin of the duplicated material. Only 14 previous cases of duplication 18p have been reported and these exhibited either a normal phenotype or mild and inconsistent abnormalities. The present cases, as well as the review of literature, indicate that duplication 18p is associated with few or inapparent phenotypic abnormalities.

Adult↗
PubMed1991

The 5' insulin gene polymorphism and the genetics of vascular complications in type 1 (insulin-dependent) diabetes mellitus.

Recent data suggest genetic contributions to the microvascular complications of Type 1 (insulin-dependent) diabetes mellitus. Most research has focused on the HLA region, and the potential role of other genetic loci has not been adequately explored. We examined the possible relationship between DNA polymorphisms in the region 5' to the insulin gene on chromosome 11 and diabetic nephropathy. This was done by comparison of those diabetic patients homozygous for class 1 alleles at the 5' insulin gene polymorphism locus to 1/3 heterozygotes in a well-characterized series of 324 insulin-requiring diabetic patients from the Wisconsin Epidemiologic Study of Diabetic Retinopathy. Proteinuria (defined as greater than or equal to 0.3 g protein/l urine), was used as suggestive evidence for diabetic nephropathy. Hypertension, a frequent associated finding in diabetic patients with nephropathy, was defined as a blood pressure greater than 140/90 or a history of previous treatment of hypertension. The two genotypically defined groups did not differ from each other in regard to sex ratio, age at diagnosis, age at examination, duration of diabetes, body mass, HbAlc or C-peptide. The 1+1 group had a higher prevalence of proteinuria, 29% as compared to 16.2% in other genotypes (p less than 0.05). There was no significant difference in the frequency of hypertension between the two genotypic groups. This finding suggests that the 5' insulin gene polymorphism may be associated with risk for nephropathy, but the pathophysiologic mechanism remains unclear.

Blood Pressure↗
PubMed1991

HLA-DR and the 5' insulin gene polymorphism in insulin-dependent diabetes.

While the human leukocyte antigen (HLA) region provides the major susceptibility for insulin-dependent (type I) diabetes mellitus (IDDM), other (non-HLA) genes must also play a role. Population studies have shown an increased frequency of small insertions (class I alleles) 5' to the insulin gene in individuals with IDDM, suggesting that this region may account for part, if not all, of the non-HLA genetic predisposition. However, no data are available as to whether the relation of the insulin gene polymorphism is to a DR-defined subset of IDDM or with all of IDDM. To test the hypothesis that specific combinations of HLA and insulin gene polymorphism alleles may interact in providing susceptibility for IDDM, HLA-DR and 5' insulin gene insertion size have been determined in 300 individuals with IDDM. The frequency of class 1 insulin gene alleles in the entire sample is 0.79 and the frequency of class 3 alleles (large inserts) is 0.20. The frequencies of class 1 alleles were equal across all DR classes: 0.79 in the DR3/X IDDM subjects, 0.80 in the DR4/X, 0.79 in the DR3/4, and 0.78 in those with DRX/X. Additionally, the frequencies of class 1/1 homozygotes and 1/3 heterozygotes were similar between HLA-DR types. These results suggest that the HLA region and the region 5' to the insulin gene provide independent and nonsynergistic genetic risks for IDDM.

Diabetes Mellitus, Type 1↗
PubMed1991

De novo 13q partial duplication identified by cytogenetic, biochemical and molecular approaches.

A 3.5-month-old female infant manifesting dysmorphic facies, developmental delay and failure to thrive was referred for cytogenetic evaluation. Peripheral lymphocytes revealed three chromosomally distinct cell lines: 46,XX/46,XX,10p+/47,XX,10p+,+mar. Dermal fibroblasts revealed only the 46,XX,10p+cell line. High resolution G-, R-, and Q-banding suggested that the extra chromosomal material (10p+) represented a duplication of the segment 13q14----13qter. Parental karyotypes were normal. As absolute identification of de novo chromosomal abnormalities, based solely on cytogenetic studies, is sometimes difficult, both biochemical and molecular approaches were undertaken to elucidate this abnormality in more detail. Dosage effects were examined using esterase D (localized to 13q14.1) and the DNA probes p1E8 and p9A7 (localized to 13q22 and 13q31/32, respectively). These studies suggested the presence of only 2 copies of esterase D, but 3 copies of both DNA probes, allowing identification of the breakpoint at 13q14.2.

Abnormalities, Multiple↗
PubMed1990

Proximal interstitial deletion of 7q: a case report and review of the literature.

A male infant with multiple congenital anomalies was found to have a deletion of 7q [46,XY,del(7)(pter----q11.2::q22----qter)]. The father had a balanced rearrangement involving chromosomes 7 and 9, interpreted as 46,XY,dir ins(9;7), (9pter----9p12::7q22----7q11.2::9p12----++ +9qter;7pter---- 7q11.2::7q22----7qter). C-banding showed that the rearrangement occurred as a new event in the paternal grandfather's germ-line. Including the present patient, 16 cases of proximal 7q deletion (q11----q21/q22) have been described to date. This is a sufficient number of cases to permit comparison of manifestations to attempt delineation of karyotype-phenotype relationships in different proximal interstitial deletions of 7q.

Abnormalities, Multiple↗
PubMed1990

A paternal balanced translocation [t(7;22)(q32;q13.3)] leading to reciprocal unbalanced karyotypes in two consecutive pregnancies.

A family is reported in which a man with a balanced reciprocal translocation [46,XY,t(7;22)(q32;q13.3)] fathered a daughter who was trisomic for the region 7q32----7qter and monosomic for 22q13.3----22qter, and a male fetus who was monosomic for 7q32----qter and trisomic for 22q13.3----22qter. The meiotic segregation of this translocation, as well as the phenotypes of the unbalanced offspring, are discussed.

Abnormalities, Multiple↗
PubMed1989

Antenatal detection of cystic hygroma.

Ultrasonographic evaluation, as a routine component of prenatal care, has significantly contributed to in utero assessment of pregnancy status. The detection of fetal abnormalities by ultrasound, however, has raised clinical questions and created parental dilemmas concerning the outcomes of such pregnancies. A relatively frequent anomaly observed on routine ultrasonographic examination is the posterior nuchal cystic hygroma. We report the prenatal detection of 16 cases of cystic hygromata and an analysis of a survey of the world's literature including an additional 155 cases. The information available from these 171 cases allows a clearer picture of the prognosis for fetuses in whom posterior cystic hygroma is detected in utero. Regarding outcome, 73.2 per cent of cases were terminated at the parents' request; 37 cases (22.6 per cent) resulted in fetal death in utero prior to any intervention. Only 7 per cent of continuing pregnancies resulted in live-born infants. Of the 142 cases with available cytogenetic findings, 22 per cent had normal karyotypes; 58 per cent had a karyotype associated with Turner syndrome phenotype; while autosomal trisomies and various structural abnormalities made up the remaining 20 per cent. Even among those fetuses with normal chromosomes, various physical anomalies were detected. Fetal hydrops was present in 66 per cent of the 102 cases with pertinent information. For those fetuses demonstrating cystic hygroma and normal karyotypes, Mendelian syndromes must be considered in the differential diagnosis. Alpha-fetoprotein evaluation of both maternal serum and amniotic fluid was not helpful in determining prognosis of these fetuses. The ultrasonographic finding of a posterior nuchal cystic hygroma, with or without accompanying fetal hydrops, is a valid indicator for a poor outcome of such pregnancies.

Adult↗
PubMed1986

Chromosomal mosaicism in the Killian/Teschler-Nicola syndrome.

We report a patient with the Killian/Teschler-Nicola/Pallister mosaic syndrome in association with a cytogenetic abnormality. This patient is the first reported to have lymphocyte mosaicism for an isochromosome of 12p. All other patients with the Killian syndrome have had normal lymphocyte karyotypes, although mosaicism for a similar isochromosome of 12p has been reported in the fibroblasts of most patients with the Killian syndrome.

Abnormalities, Multiple↗
PubMed1986

Immature renal tissue in colonic wall of patient with caudal regression syndrome.

We report an incidental microscopic finding of ectopic renal tissue in a newborn with multiple congenital anomalies. The ectopic renal tissue was located in the wall of the distal blind end of the colon. The tissue was composed of undifferentiated renal blastema with primitive and well-formed glomeruli and tubules. The potential for malignant transformation of this lesion into extrarenal Wilms' tumor is not known.

Abnormalities, Multiple↗
PubMed1986

Relationships between the human pepsinogen DNA and protein polymorphisms.

Pepsinogens (PGA) are the inactive precursors of pepsin, the major acid protease found in the stomach. The PGA gene family exhibits polymorphic variation in human populations that can either be demonstrated by electrophoretic analysis of the proteins or by analysis of the respective genes with cDNA probes. Here, we describe the interrelationships between the most common pepsinogen protein phenotypes and the corresponding pepsinogen haplotypes (A, B, and C) containing different combinations of the PGA3, PGA4, and PGA5 genes. We propose that this unusual genetic variation involving haplotypes that contain three, two, and one genes, respectively, is the result of molecular evolution by gene duplication.

Chromosomes, Human, 6-12 and X↗
PubMed1976

Influence of arginine vasotocin on a genetically determined excessive appetite for water in chickens.

Females from two inbred strains of chickens, one normal and one having hereditary diabetes insipidus, were treated with five levels (2.5, 1.0, 0.5, 0.25, and 0.1 units) of Schwartz-Mann (Grade A, 100 units/mg.) arginine vasotocin via ic. injections at 2-hr. intervals. Paired sibs, one normal and one having diabetes insipidus (di), from an F2 population were used in one experiment to compare responses at the level of 2.5 units. Only di females were used for the remaining four levels of treatment. Water intake was determined every two hours and calculated as a percentage of water (ml.)/body wt. Results show that hereditary diabetes insipidus in chickens is arginine vasotocin-sensitive at the 0.5 unit and higher levels. The genetic defect appears to affect the quantity of antidiuretic hormone produced.

Animals↗