ABSTRACT
Fragile-X syndrome is caused by an unstable CGG trinucleotide repeat in the FMR1 gene at Xq27. Intermediate alleles (51-200 repeats) can undergo expansion to the full mutation on transmission from mother to offspring. To evaluate the effectiveness of a fragile-X carrier-screening program, we tested 14,334 Israeli women of child-bearing age for fragile-X carrier status between 1992 and 2000. These women were either preconceptional or pregnant and had no family history of mental retardation. All those found to be carriers of premutation or full-mutation alleles were offered genetic counseling and also prenatal diagnosis, if applicable. We identified 207 carriers of an allele with >50 repeats, representing a prevalence of 1:69. There were 127 carriers with >54 repeats, representing a prevalence of 1:113. Three asymptomatic women carried the fully mutated allele. Among the premutation and full-mutation carriers, 177 prenatal diagnoses were performed. Expansion occurred in 30 fetuses, 5 of which had an expansion to the full mutation. On the basis of these results, the expected number of avoided patients born to women identified as carriers, the cost of the test in this study (U.S. $100), and the cost of lifetime care for a mentally retarded person (>$350,000), screening was calculated to be cost-effective. Because of the high prevalence of fragile-X premutation or full-mutation alleles, even in the general population, and because of the cost-effectiveness of the program, we recommend that screening to identify female carriers should be carried out on a wide scale.
Subject(s)
Fragile X Syndrome/genetics , Gene Frequency/genetics , Genetic Testing/economics , Heterozygote , Mutation/genetics , RNA-Binding Proteins , Adult , Alleles , Cost-Benefit Analysis , DNA Mutational Analysis , Female , Fetal Diseases/diagnosis , Fetal Diseases/epidemiology , Fetal Diseases/genetics , Fetus/metabolism , Fragile X Mental Retardation Protein , Fragile X Syndrome/diagnosis , Fragile X Syndrome/epidemiology , Gene Dosage , Genetic Counseling , Humans , Israel/epidemiology , Jews/genetics , Molecular Sequence Data , Nerve Tissue Proteins/genetics , Pregnancy , Prenatal Diagnosis/economics , Prevalence , Trinucleotide Repeat Expansion/geneticsABSTRACT
A new, low-cost, noninvasive system is described, which accurately monitors and records both the initial respirations and heart rate of the neonate during resuscitation and the first critical seconds of life. The apparatus consists of a vacuum stethoscope attached to an ordinary cassette tape recorder and a 12-inch loudspeaker. The system was found to be a more accurate tool for assessing neonatal heart rate than the empirical estimation as part of the Apgar scoring system. In 6 of 37 births monitored, recordings indicated discrepancy between the actual heart rate and that estimated in the Apgar scoring system.
Subject(s)
Auscultation/instrumentation , Heart Rate , Infant, Newborn , Monitoring, Physiologic/instrumentation , Respiration , Asphyxia Neonatorum/diagnosis , Humans , Phonocardiography , ResuscitationSubject(s)
Heart Auscultation/instrumentation , Infant, Newborn , Resuscitation/methods , Heart/physiology , Humans , Time FactorsABSTRACT
A simple apparatus consisting of a vacuum stethoscope attached to an ordinary cassette tape recorder is described. This can be used for monitoring respiration and pulse rate during paediatric anaesthesia, head and neck surgery and resuscitation of the newborn.
