Children With Down Syndrome Can Learn
Congenital anomalies associated with HD have been reported from various series and have an overall incidence of about 14.7 in 2856 patients.31 Down syndrome is the most common chromosomal abnormality associated with HD, and the genetic modifiers have been located on chromosome 21q 22.32 The diagnosis of HD in Down syndrome is often delayed because other associated anomalies take precedence and because constipation is often present in these patients due to hypotonia and hypothyroidism. Cardiac abnormalities have been reported in the range of 0.5 to 1.0 of the general population, and the incidence is increased in patients with Down syndrome. The common defects are endocardial cushion defects and patent ductus arteriosus. Hirschsprung's disease is often associated with other neurocristopathy manifestations, such as pheochromocytoma, neuroblastoma, neurofibromatosis, and MEN II. Waardenburg syndrome, caused by a gene on chromosome 2, is also associated and is charac
Ophthalmic use Infants less than 3 months of age, primary glaucoma or a tendency toward glaucoma, adhesions between the iris and the lens, geriatric clients and others where undiagnosed glaucoma or excessive pressure in the eye may be present, in children who have had a previous severe systemic reaction to atropine. Special Concerns Use with caution in infants, small children, geriatric clients, diabetes, hypo- or hyper-thyroidism, narrow anterior chamber angle, individuals with Down syndrome.
Several case reports have described fetuses or infants with HHV-6 infection, yet most have no abnormalities. Aubin et al. (25) first described in utero infection with HHV-6. These investigators examined 52 electively aborted fetuses from HIV-infected women from France and noted one fetus (26 weeks) with HHV-6 DNA distributed throughout fetal tissues. No abnormalities were identified. One study from Japan identified HHV-6 antigens in tissues from 2 of 30 (7 ) fetuses spontaneously aborted at 6-12 weeks fetal abnormalities were not described (26). HHV-6 DNA has also been found in fetal tissues of two of eight cases (25 ) of fetal hydrops (17 and 19 weeks of gestation) (27). However, both fetuses also had a chromosomal abnormality (Down syndrome and Turner's syndrome) possibly contributing to the hydrops. Fulminant hepatitis in two neonates (aged 3 and 5 days) has purported to be linked to congenital HHV-6 infection based on HHV-6 viremia in mother and baby (28) further...
The incidence of congenital hypothyroidism (CH) as detected by common neonatal screening programs, is approximately 1 3,000-1 4,000 in live births 1 . Very recently, in the Netherlands a higher incidence of 1 1,800 was observed using a screening based on thyroxine (T4), thyrotropin (TSH) and thyroxine-binding globulin (TBG) measurement 2 . With this strategy, the incidence of various types of CH was estimated 1 2,200 for permanent CH with 1 2,500 of thyroidal origin, 1 21,000 of central origin, and 1 12,000 for transient hypothyroidism. For unknown reasons, the female male ratio in CH is consistently 2 1. Newborn infants with Down syndrome have an increased risk for CH of approximately 1 140.
Encephalomyocarditis (EMC) virus (ATCC VR 129B) Human interferon reference standards (available from Dr. C. Laughlin, National Institute of Allergy and Infectious Diseases, Bethesda, MD) Human diploid fibroblast (FS-4 Havell and Vilcek, 1972), trisomy 21 human line (GM2504 Preble et al., 1982), or human lung carcinoma line (A549 ATCC CCL 185) 2. Assay human cells using EMC virus following steps 8 to 15 of the basic protocol and noting precautions for handling viruses. To assay for human IFN-a and IFN-P, use a human diploid fibroblast line such as FS-4, or for extreme sensitivity, use a trisomy 21 human line such as GM2504. To assay human IFN-y use A549, a human lung carcinoma line.
Triple screen (a-fetoprotein, human chorionic gonadotropin hCG , estriol). In women under age 35 years, screening for fetal Down syndrome is accomplished with a triple screen. Maternal serum alpha-fetoprotein is elevated in 20-25 of all cases of Down syndrome, and it is elevated in fetal neural tube deficits. Levels of hCG are higher in Down syndrome and levels of unconjugated estriol are lower in Down syndrome. 2. If levels are abnormal, an ultrasound examination is performed and genetic amniocentesis is offered. The triple screen identifies 60 of Down syndrome cases. Low levels of all three serum analytes identifies 60-75 of all cases of fetal trisomy 18.
Disease elimination suits diseases with single known causes (pathogens) that can be specifically targeted in a prevention strategy. This has been the model used in infectious diseases such as smallpox, which was eliminated from the community by population vaccination programs, and in other diseases such as measles, rubella, polio and diphtheria, which can be prevented in most individuals by vaccination. This will also be the model used in proposed gene therapies for genetic disorders where a single gene mutation is responsible for the disease. The gene therapy will target the mutation and correct the abnormality before it has had the opportunity to cause irreparable damage. Another method of disease elimination involves DNA testing of a foetus during early pregnancy where a known genetic risk for a disorder, such as Down syndrome, exists leading to a possible termination of the pregnancy.
Most of the highly publicised advances in the genetics of Alzheimer's disease have come from the study of very rare families with so-called Familial Alzheimer's disease (FAD). FAD is an autosomal dominant disease, which means that 50 per cent of each generation develop Alzheimer's disease, usually between the ages of 40 and 60 years. Causative mutations on chromosome 14 (presenilin-1 gene), chromosome 1 (presenilin-2 gene) and chromosome 21 (amyloid precursor protein gene) have been found in these families. Hints that chromosome 21 could be implicated came with the finding that there was a higher rate of Down syndrome, a genetic disorder due to abnormalities on chromosome 21, in the family history of Alzheimer patients, and with the observation that the majority of persons with Down syndrome who survive to late adulthood develop dementia.
Tubes, particularly in infants and young children, because the amount and stiffness of their cartilage is less than that of older children and adults. Eustachian tube obstruction leads to negative middle ear pressure and a sterile MEE. Drainage of the effusion is inhibited by impaired mucociliary action and sustained negative pressure. Contamination of the middle ear may occur from nasopharyngeal secretions and lead to infection. Because infants and young children have a shorter eustachian tube than older children, it makes them more susceptible to reflux of nasopharyngeal secretions into the middle ear and development of infection. Other predisposing factors include upper respiratory infections, allergies, Down syndrome, bottle propping during feedings, daycare attendance, and parental smoking. Complications include persistent AOM, tympanic membrane perforation, mastoiditis, hearing loss for several months, speech delay, and cerebral thrombophlebitis.
85 of cases of mental retardation are mild (IQ range 55-70) and are usually idiopathic. Patients often have a reasonable level of independence with assistance or guidance during periods of stress. Fetal alcohol syndrome is the number-one preventable cause, whereas Down syndrome is the number-one overall cause. Fragile X syndrome (in males) is another common cause of mental retardation.
A triple or quadruple maternal serum screen should be offered to help detect neural tube defects and Down syndrome (ie, triple screen alpha-fetoprotein + unconjugated estriol + human chorionic gonadotropin inhibin A is added for a quadruple screen).