Rapid and Simple Prenatal PCR-based DNA Diagnosis - Down Syndrome
L. Verma et al. assure us that from a study of 2167 women undergoing amniocentesis for prenatal studies, 2083 amniotic fluids were not macroscopically blood-stained, 30 instances of trisomy 21 were diagnosed by two DNA markers, that only 28 samples were unsuitable for analysis and that there were no false-positive nor false-negative results (Lancet 352: 9, 1998).
Routine Neonatal Examination, Is once Enough? Is it useful?
In an editorial, D.M.B. Hall (BMJ 318: 619, 1999) reviews a study in Aberdeen, Scotland, and concludes that one neonatal examination is sufficient and useful.
Parkinson Disease (PD) in Twins, Genetics Plays no Part but ...
From an investigation of nearly 20,000 white male twins, C. M. Tanner et al. (JAMA 281: 341, 1999) noted that "... the mean age at diagnosis... was about 65 years... 25% were diagnosed after age 70 years... the current study suggests that typical PD diagnosed after age 50 years has no genetic component, quite the opposite was observed... when diagnosed before age 51 years... genetic factors appear to be important... but shared environmental factors... could produce the same pattern."
Hermansky Pudlak Syndrome (HPS) - Oculocutaneous Albinism - Puerto Rico - Further Molecular Characterizations
The accumulation of ceroid lipofuscin is associated with HPS or oculocutaneous albinism. The genetic mutation is more common in Puerto Rico. The broad range of altered pigmentation and restrictive lung disease among 25 patients and a 16-bp duplication in exon 15 exclusively found among Puerto Rican patients is reviewed by Drs. W. A. Gahl et al. (N. Eng. J. Med. 338, 1258, 1998).
Down Syndrome - Dementia - Cholinergic Therapy
According to Dr. P S Kishnani et al., a randomized placebo-controlled study of cholinergic therapy in Down's syndrome is warranted. Their conclusions are based on a prospective open trial of "donopezil" on four adults with trisomy 21 and Down's syndrome, two of these four patients met the DSM-IV criteria for dementia. The investigators consider that improvements in communication, expressive language, attention and mood stability were significant (Lancet 353: 1064, 1999).
The reintroduction of Thalidomide and concerns regarding other teratogenic agents may perhaps, at times, create a need demand for "emergency contraception". An Editorial by Anne Webb, a consultant in family planning in Liverpool, Great Britain (BMJ, 318: 342, 1999) discusses the merits of the "Yuzpe" method (combination of estrogen and rogestogen), mifepristone and levonorgestrel.
Mitochondria - A Comeback The essence of cell viability and death - Inheritance - Evolution Phosphorilation - Fertility - Aging Behavior - Diseases
Timely and useful authoritative reviews by a panel of experts was recently published in Science (283: 1475, 1999). An emerging area of mitochondrial research relates to spermatogenesis and human infertility, a theme highlighted elsewhere in this issue.
Non-disjunction in Spermatogenesis Not Random - Sex Chromosomes - Chromosome 21
From studies of disomic human sperm, E. L. Spriggs et al. (Am. J. Hum. Genet. 58: 356, 1996), conclude that sex chromosome and chromosome 21 are especially susceptible to nondisjunction.
Fetal Alcohol Syndrome (FAS) - Impaired Spatial Memory
From a study of 30 patients, Drs. A. Uecker and L. Nadel (Am. J. Ment. Retard. 103: 12, 1998) conclude that spatial but not object memory is a component of FAS, a finding concordant with previous animal studies. In contrast, patients with Down syndrome have deficits in both spatial and object memory.
Prader Willi Syndrome (PWS) - Maternal Uniparental Disomy Dampens Behavior Effects
From a study of 23 patients with PWS, Dr. E. M. Dykens et al. (Am. J. Ment. Retard. 104: 67, 1999) conclude that "deleted cases are more apt to skin-pick, bite their nails, hoard, overeat, sulk, and withdraw. A dampening of symptom severity is suggested in PWS cases due to maternal uniparental disomy".
Natural History of Wolf-Hirschhorn Syndrome
Based on 15 patients drawn from three centers, Dr. A. Battaglia et al. (Pediatrics 103: 830, 1999), offer a clinically useful overview; heart lesions were common (33%) as were oro-facial clefts (47%); convulsions tended to disappear with age; two patients were able to walk with support; one was deaf; two had sphincter control during the day.