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An infant girl with ring chromosome 14 is presented. The findings in this patient and in six previously reported cases of a ring 14 suggest that a characteristic clinical syndrome is associated with this chromosome aberration. The major features of the ring chromosome 14 syndrome include mental retardation, a disorder of skin pigmentation, seizures, and dysmorphic features, including flat occiput, epicanthal folds, downward slanting eyes, flat nasal bridge, upturned nostrils, short neck, and large low set ears. [ABSTRACT FROM PUBLISHER]

A pair of monozygotic, adolescent twins is discordant for sex. The phenotypic female twin has chromosome constitution of 46, XY/45, X. She displays many signs of Turner's syndrome, including typical facies, webbed neck, malformed left kidney, high plasma gonadotropins, and streak ovaries. However, her height is 154 cm which exceeds the height usually reported in Turner's syndrome. The male twin has a karyotype of 46, XY and normal sexual development. Only two other reports of pairs of monozygotic twins of opposite sex have been published. [ABSTRACT FROM PUBLISHER]

An adult female with typical features of Silver-Russell dwarfism gave birth to a viable infant. Despite the abnormalities in sexual development that may be associated with the Silver-Russell syndrome, fertility is not necessarily impaired, at least in females. The growth and development of children with the Silver-Russell syndrome have been studied (Silver, 1964; Tanner et al., 1975). There is, however, virtually no information available about adult patients with this syndrome. It is known that both male and female Silver-Russell dwarfs develop secondary sexual characteristics (Rimoin, 1969; McDowell and Sproles, 1973) but fertility of these patients has not been described previously. [ABSTRACT FROM PUBLISHER]

The association of interleukin-10 (IL-10) promoter single-nucleotide polymorphisms (SNPs) as risk factors for certain inflammatory diseases, viral infections, cancers, and transplant rejection have been the subject of recent studies. The SNPs -1082 G --> A, -819 C --> T, and -592 C --> A, which have been associated with differential IL-10 production, are strongly linked with ethnicity. In this study, we determined the ethnic distribution of IL-10 promoter SNPs and their haplotype rates among Hispanics, African Americans, and Caucasians from Texas and Ashkenazi Jews from New York. Significant differences in prevalence rates of IL-10 SNPs (and their haplotype distribution) were found. African Americans and Hispanics have a lower rate of putative high-producer SNPs and a higher rate of low IL-10 producers when compared to Caucasians or Ashkenazi Jews. No statistically significant differences in allelic frequencies and haplotype rates were observed between Caucasians and Ashkenazi Jews. This study provides critical new information on the ethnic distribution of IL-10 promoter SNPs in a regional U. S. population and is the first to analyze the rate of SNPs in an unstudied ethnic population, Ashkenazi Jews. Knowledge of IL-10 promoter polymorphisms may prove useful in prediction of immunization responses, disease severity, and in the intelligent design of customized immunotherapy.

The importance of hyperhomocysteinemia, birth defects, and vascular diseases has been the subject of intense investigations. The polymorphic MTHFR mutations (C677T and A1298C) cause mild hyperhomocysteinemia, especially in homozygotes for C677T, but also in compound heterozygotes for C677T/A1298C. The subject of this report is the frequency of the polymorphic mutations in the MTHFR gene C677T, C1298A, and newly discovered mutation G1793A, as well as the association with MTRR polymorphic site A66G in different ethnic groups. Four ethnic groups were studied: African-Americans, Caucasians, Hispanics, and Ashkenazi Jews. There are statistically significant differences in the frequency of these alleles in the different populations studied, which impacts compound heterozygosity for such alleles in these populations. DNA samples obtained from the blood of healthy individuals of African-Americans, Hispanics, and Caucasians from south Texas were analyzed and compared to those obtained from Ashkenazi Jewish individuals. The polymorphic site, the G1793A allele, is least frequent among Ashkenazi individuals, 1.3%, compared to 6.9% among Caucasians (P = 0.001), 5.8% among Hispanics (P = 0.012), and 3.1% among African-Americans. The MTRR polymorphic site shows the lowest allele frequency among Hispanics, 28.6%, compared to 34% among African-Americans, 43.1% among Ashkenazi Jews (P = 0.002), and 54.4% among Caucasians (P < 0.0001). Statistically significant differences in allele frequencies of C677T and C1298A polymorphisms were also observed in these populations. Compound heterozygosity for multiple polymorphic alleles may play a role in birth defects and vascular diseases., (Copyright 2001 Wiley-Liss, Inc.)

The polymorphic mutation C677T in the gene of MTHFR is considered a risk mutation for spina bifida and vascular disease. Another common mutation on the MTHFR gene, A1298C, has also been described as another risk mutation. We studied the frequencies of these two mutations on DNA samples from healthy Jewish individuals and compared them to the frequency of these mutations in DNA samples obtained from healthy individuals in South Texas. The presence of the C677T allele was determined by PCR and Hinf I digestion, and mutation A1298C by PCR and Mbo II digestion. A total of 310 alleles was examined for C677T in the Ashkenazi samples and 400 alleles in the non-Jewish samples. The rate of C677T among the Ashkenazi Jewish alleles was 47.7% as compared to 28.7% among the alleles from the non-Jewish population. The difference is statistically significant, P < 0.0005. Mutation A1298C was examined in 298 alleles of Jewish individuals and 374 alleles of non-Jewish counterparts from Texas. The rate of the A1298C mutation in the Jewish samples was 27.2% whereas in the non-Jewish was 35%. This was also statistically significant, P < 0.031. No individuals were homozygous for both mutations or were found to be homozygous for one mutation with heterozygosity of the other mutation, and that the C677T and the A1298C alleles did not occur in cis position. This study shows a unique distribution of C677T and the A1298C alleles among the Ashkenazi Jews. In spite of high frequency of C677T mutation, spina bifida is less common among Ashkenazi Jews. Further studies are needed to establish whether the C677T and the A1298C mutations have an impact on vascular disease in the Ashkenazi Jewish population., (Copyright 1999 Wiley-Liss, Inc.)