No abstract

Mutations in hMSH2 and hMLH1 genes were analyzed in patients from 11 Japanese families that had been diagnosed as carrying hereditary nonpolyposis colorectal cancer (HNPCC) by clinical examination. Germ line mutations of hMSH2 gene were identified in 5 independent families in which colorectal (87% of patients), endometrial (30%), ovarian (17%), gastric (14%), and other cancers existed. Five mutations detected between codons 136 and 811 included single-base substitutions (C-->T and T-->G), a T deletion, and an A insertion, all of which produced stop codons resulting in truncated proteins, and an A-->T substitution at splice donor site of exon 5 which resulted in deletion of this exon. Moreover, one HNPCC family was presumed to have germ line mutation of hMSH2 gene because a somatic mutation of hMSH2 gene was detected in a cancer from a patient in this family. In addition to these 11 families already diagnosed with HNPCC, 3 new families with germ line mutations of hMSH2 gene and hMLH1 gene were found through analysis of DNA from patients who had multiple cancers with alteration in microsatellite DNA. These mutations included an AG deletion at codons 877-878 of hMSH2 gene, an AAG deletion at codons 616-618 of hMLH1 gene, and a C-->T single-base substitution at codon 217 of hMLH1 gene. Seven of eight germ line mutations found in this study are new mutations that have not been reported previously. In families in which germ line mutations were identified presymptomatic examination was then carried out using polymerase chain reaction single-strand conformation polymorphism analysis of DNA from peripheral blood, and the result was the detection of family members predisposed to HNPCC who did not yet show signs of cancer. These results indicate the value of DNA analysis in the screening and diagnosis of HNPCC patients and families.

We sought to define the current standard of care for children undergoing sedation for painless diagnostic procedures by sending questionnaires to 284 pediatric residency program directors in North America. From the 89 responses, we determined that departments of pediatrics set sedation policies for children in most institutions, often with formal written guidelines for these procedures. Most require that children have some form of cardiorespiratory monitoring while under sedation and that they are attended by individuals trained in cardiorespiratory resuscitation until the child is fully recovered. The use of parents to transport and monitor the sedated child is uncommon, and total lack of monitoring is rare. Chloral hydrate in dosages of 25 mg/kg to 100 mg/kg is the most common drug used for sedation; DPT, a combination of parenteral Demerol (meperidine), Phenergan (promethazine), and Thorazine (chlorpromazine), at a maximum dose of 2 mg/1 mg/1 mg/kg is the second; and pentobarbital in a dosage of 5 mg/kg to 7 mg/kg is the third. These sedation regimens were associated with few serious side effects, except that two deaths were reported in infants with congenital heart disease who were sedated with DPT. We believe this survey may reflect the current standard of practice for sedation in North American infants and children undergoing diagnostic procedures.

The clinical, electromyographic, and histologic characteristics of a 17-year-old girl with reducing body myopathy are described. She is, to our knowledge, the oldest reported case and the only patient described with severe mitral valve prolapse and scoliosis. Electromyography demonstrated spontaneous positive sharp waves and fibrillation potentials with many low-amplitude, short, polyphasic motor unit potentials. The right deltoid muscle was characterized by focal areas with large fibers associated with increased endomysial connective tissue and "split" fibers. Purple-gray sarcoplasmic masses stained with trichrome were PAS-negative, appeared as "empty" spaces with both ATPase and NADH-TR, and stained darkly with menadione NBT. The features described expand the clinical presentation of this myopathy, and may lead to a better understanding of its etiology.