Tear function abnormalities in down syndrome

Down syndrome is a common chromosomal anomaly, characterized by specific facial features, eye anomalies with repeated ophthalmic infections. The integrity of the ocular surface is maintained by the tear film. To determine the presence of tear function changes in children with Down syndrome and their relation with the development of ophthalmic diseases. Tear film was evaluated by the ferning test and breakup time [BUT] measurement in 23 patients [46 eyes] confirmed as having Down syndrome by cylogenetic analysis and 20 normal control children [40 eyes] with matched age and sex. There was an alteration in both ferning and BUT tests in children with Down syndrome compared to controls. Abnormal ferning test was found in 28 out of 46 tear samples from the patient's eyes compared to 2 out of 40 normal control eyes. BUT test results showed that the preocular tear film stability was poor in 65.2% of patients' eyes, average in 26.1% and good in only 8.7% of their eyes; while controls had good and average tear film stability each representing 50% of eye's number. These tear function abnormalities may have a role in the frequent infectious pathologies found in the anterior eye segment in patients with Down syndrome which necessitates applying new stringent strategies for ophthalmologic care and management of these patients

Bone mineralization and body composition in turner syndrome

Females with Turner syndrome are at risk for decreased bone density from ovarian failure and possibly from haploin-sufficiency for bone-related X-chromosome genes. We studied the relation between bone density, anthropometry, body composition and chromosomal abnormalities in Turner syndrome. The study included 18 females with Turner syndrome. They were divided in two groups. Group A consisted of 12 cases with 45, X karyotype [classic Turner syndrome] and their mean age of 13.5 +/- 5.5 years. Group B included 6 cases with mosaic karyotype and their mean age of 16.3 +/- 4.2 years. Bone mineral density [BMD] was determined using dual energy X-ray absorptiometry scans [DEXA]. BMD was measured in the femoral neck [FN], lumber spine [LS], and forearm [FA]. Body composition was assessed using RJL body fat analyzer. Anthropometry was carried out for each case. Seventy-two percent of females investigated had osteope-nia. When BMD was expressed as z-scores [individual values compared to normal reference data matched for age and weight] for all cases at it was 0.587 +/- 0.10 at FN and was 0.630 +/- 0.17 at LS. In group A bone mineral density was decreased [osteope-nia] by 66.7% in FN, and 25% in LS. In group B bone mineral density was decreased by 66.7% in FN, and 50% in LS. When comparing females in group A with those of group B, there was no statistical difference in BMD at femur and spine. The ostopenia found in patients of group A and B was not related to type of X-chromosomal aberrations. Group A showed significant increase in TBW and Corinic index SDS as compared to group B. Body fat and lean percentages are similar in the two studied groups. Also, no correlation was found between BMD and body weight, body height, body fat or percentage body fat. Body composition changes seem to be more impressive in classic Turner patients, while BMD changes are similar in the two groups. Achieving optimal bone density is of critical importance for fracture prevention in TS

Hereditary non-syndromic hearing loss: influence of different variables

Non-syndromic hearing loss [NSHL] was studied in twenty-five patients using a clinical, audiological, cytogenetic and neurobiochemical evaluation. The study group was divided into five subgroups according to severity of hearing loss. Positive parental consanguinity was present in 84% of cases and similarly affected family members were present in 76%. All patients had no congenital malformations and were not dysmorphic. Patients possibly exposed to environmental factors were excluded from the study. Abnormal karyotyping was present in three cases, one case showed chromosome 15p 4, another case showed chromosomal del 11q22.1 and in the third case [47,XY] there was marker chromosome 15. Fluorescence in situ Hybridization [FISH] technique was performed on the case which showed marker. The study group showed significant lowering of five plasma amino acid levels [glutamic acid, aspartic acid, histidine, 3-methylhistidine and carnosine]. There was significant correlation between severity of hearing loss and each of the following: patient's age, glutamic acid, aspartic acid, 3-methylhistidine and carnosine. Identification of NSHL early after birth, as well as, amino acid screening is essential, to allow for faster therapeutic intervention and proper genetic counseling

Clinical and biochemical variability of the classical smith-lemli-opitz syndrome in Egyptians

Smith-Lemli-Opitz syndrome [SLO] is the first true metabolic malformation syndrome. The underlying defect is absent or deficient activity of 7-dehydrocholesterol reductase, which is the enzyme catalyzing the last step of cholesterol synthesis. We report on the first Egyptian cases [seven males] with SLO. We studied the clinical and biochemical variability of the syndrome and its relation to patients' age. Mental retardation, 2/3 toe syndactyly and genital anomalies were present in all patients. The distinct facial appearance became less obvious with age. All patients had marked elevation of plasma 7-dehydrocholesterol, which were measured by use of ultraviolet spectrometry. Plasma cholesterol measured by calorimetric method, were within the low normal range in most patients. Dietary cholesterol supplementation in two patients resulted in improvement of behaviour, better tolerance of infection, diminution of photosensitivity, pubertal progression and improvement in plasma sterol levels. The clinical phenotype of SLO is widely variable and plasma cholesterol levels are not reliable for detection of the syndrome. Therefore, diagnosis of SLO by demonstrating increased plasma concentrations of 7-dehydrocholesterol using ultraviolet spectrometry is a rapid and reliable method. Increased awareness of SLO is required for early diagnosis and dietary treatment of affected individuals