The C677T variant in the MTHFR gene is considered to be an associated risk factor for neural tube defects. However, the association has not been found in some ethnic groups. In order to assess the association between neural tube defects and the C677T variant, we determined the frequency of this variant in the MTHFR gene in the State of Yucatan, Mexico, where neural tube defects are highly prevalent. The study was performed on 65 subjects with spine bifida, 60 of their mothers and 110 control subjects. The presence of the C677T variant was determined by amplification and digestion with HinF1 of each subject's DNA. Genotypic and allelic frequencies were calculated for all groups. We did not observe any statistically significant difference in the genotypic or allelic frequencies between cases and controls for any of the groups studied (p > 0.05), suggesting that the thermolabile variant C677T is not an associated risk factor neither for the development of neural tube defects nor for mothers to have affected offspring in the population from Yucatan. Interestingly, the frequency of the C677T variant (54%) obtained in the Yucatan population is one of the highest reported (p < 0.01) and confirmed the high frequency of this allele throughout Mexico.

Most cases of KTW syndrome are sporadic. However, in a few, other family members have some clinical manifestations of the syndrome, and an autosomal dominant mode of inheritance has been suggested. In this paper we present a family with an affected child who has large skin hemangiomata, overgrowth of the right leg, and severe heart defects. Her mother has a large capillary hemangioma on the left side of back and has developed severe varicosities in both lower extremities. The maternal grandmother developed severe varicosities in her legs at a young age. The clinical signs found in the mother represent a milder phenotype and might be explained as variable expressivity of the syndrome. The family tree supports autosomal dominant inheritance. © 1996 Wiley‐Liss, Inc.

We describe an abnormal premature male infant with mosaic monosomy of chromosome 22. He had a unique facial appearance, similar to those with DiGeorge syndrome, and hypertonicity, limitation of extension at major joints, and flexion contractures of all fingers. This rare chromosomal aberration has been reported previously in 6 cases, three of them being nonmosaic and three mosaic patients. There was a great variability of expression among the anomalies of these patients. However, the most common anomalies were in the face and joints. A correlation between the severity of expression and percent of monosomic cells was not clear.

We report on a 3-month-old girl with a TAR-like syndrome. Her older brother died with a similar disorder at 3 months of unknown causes. The parents are second cousins of Mayan ancestry. The infant also had, in addition to the usual abnormalities of TAR syndrome, depressed nasal bridge, cataracts, glaucoma, megalocorneae, and blue sclerae.

No abstract