Diagnosis and treatment of ear disease among children in the Ellisras district. An outreach programme.

Audiologists and ENT registrars examined 2,036 children aged 10 years or younger by means of pure-tone audiometry, tympanometry and otoscopic examinations. Twenty per cent of these children had ear pathology and 7.5% had impaired hearing. Forty-three pus swabs taken from patients with suppurative otitis media most often cultured Proteus mirabilis and Pseudomonas species. The prevalence of otitis media with effusion was twice as high in white children as in black children, resulting in a much higher prevalence of hearing loss in the first group. The black children had 7 times more dry perforations of the tympanic membrane and 11 times more wet perforations. A hundred and thirty-six patients were treated by the team and 137 were referred for further treatment. Sixteen operations were performed at a later stage. Further programmes are needed to diagnose and treat ear disease in rural communities.

Down's syndrome in South Africa--incidence, maternal age and utilisation of prenatal diagnosis.

Down's syndrome (DS) is the most common chromosomal cause of metal retardation, and amniocentesis is the most significant factor affecting its prevalence. In South Africa, prenatal cytogenetic diagnoses have been available for just over a decade and the utilisation and effect of this procedure in the white population born between 1980 and 1984 was evaluated. On the basis of pooled data involving 4,939,640 births, an overall world mean rate for DS of 1,34/1,000 live births (mainly Caucasian) for single-year maternal ages was calculated. Accordingly, 58 cases of DS were expected in the 40-year and older maternal age group in South Africa. Only 34 cases (59%) were detected prenatally, and a further 3 cases were identified by the notification system during the same period and in the same maternal age group. Another 24 DS cases in the maternal age group of 40 years and over could thus potentially have been detected prenatally and prevented, while 21 cases in this age group (36%) could not be accounted for at all. Cost-benefit analyses are shown and the number of amniocenteses required for various maternal age groups to affect the prevention of DS is calculated.

Birth defects surveillance. A pilot system in the Cape Peninsula.

A pilot birth defects surveillance system was established in 1982 as part of an epidemiological baseline study pertaining to potential changes in water quality in the Cape Peninsula. The methodology used for reporting birth defects for two information systems, one hospital-based and the other population-based, utilizing statutory notifications of births, is described. Preliminary birth defect rates by cause are presented for a hospital-based system and are consistent with rates reported internationally. The system based on statutory notifications showed gross under-reporting.

On the prevention of rhesus immunisation in the RSA.

The utilisation rate of anti-Rh antiserum in South African population groups for the years 1983-1985 was investigated. The number of pregnancies at risk of fetomaternal sensitisation because of Rh incompatibility and hence the number of women requiring prophylactic treatment with anti-Rh anti-serum shortly after delivery can be calculated from the known frequency of Rh-negative subjects in each population group. By relating the number of doses of anti-Rh antiserum actually distributed and used to the number of women requiring this prophylactic treatment, the crude utilisation rate of anti-Rh antiserum is calculated as 41-44% for all population groups combined. The rate for blacks is calculated at 14-20%, for whites 89-94%, for Indians 59-64% and for Coloureds 45-51% (the range of variation covers the years 1983-1985). These figures are discussed in terms of the approximations made for the calculations (hence 'crude utilisation rate'), the experience in other countries (specifically the USA) and the need for improving this facet of primary health care.

Neonatal screening for congenital hypothyroidism. A decade's review, including South Africa.

Since its introduction in 1974, neonatal screening for congenital hypothyroidism has been very extensively conducted world-wide. It is the commonest disorder found in all neonatal screening programmes, occurring in 1:3,000-8,000 births. Laboratory testing for thyroid function within the first 5 days after birth identifies this disorder weeks to months before clinical symptoms become evident and the clinical diagnosis is made. A screening programme in Pretoria (February 1981- October 1986) has identified 11 hypothyroid neonates in some 45,577 infants tested. Internationally, there is now a 10-year experience (and a follow-up for a number of programmes) of neonatal hypothyroidism diagnosed by laboratory screening tests and treated within weeks of birth. There is conclusive evidence that the physical and mental development of these children is within, or approaches to a great degree, normal limits.

Alpha-1-antitrypsin genetic polymorphism in South Africa.

The alpha 1-antitrypsin (AAT) or protease inhibitor (Pi) genetic polymorphism was studied in 144 white, 100 coloured, 104 Indian and 127 black (Northern Sotho) healthy individuals (controls), in the Pretoria area. Their Pi phenotype and gene frequency distributions are compared with world-wide data on other population groups. The severely deficient Pi phenotypes S, Z and SZ jointly attain frequencies of 0.3-0.4% in coloureds and whites; in blacks and Indians the corresponding frequencies are very much lower. The implication for preventive medicine and public health is that in South Africa the sequelae of Pi deficiencies such as cirrhosis of the liver and/or emphysema of the lung are of practical importance in whites and coloureds and much less so in blacks and Indians. In 176 white breast cancer patients studied, the Pi phenotype and gene frequency distributions were found to be similar to those of healthy controls (not statistically significant). Cohorts of other patients were also phenotyped because of their low alpha 1-globulin concentrations in routine serum protein electrophoresis and/or their specific disease condition (cirrhosis of the liver or emphysema of the lung) known to be associated with AAT deficiency. These results are discussed in terms of their significance for family follow-up, genetic counselling and a preventive service. The need to avoid atmospheric pollution, especially cigarette smoke, is emphasised as a major and cost-effective preventive measure.

The Martin-Bell syndrome in South Africa.

A national screening programme was introduced in 1980 when the first cases with the Martin-Bell syndrome were diagnosed in South Africa. This survey includes patients from all the major population groups in South Africa. One thousand patients, who include 354 relatives of 21 index cases, were investigated cytogenetically. About 75% of the 354 relatives were either affected males or obligate or possible carriers. The segregation pattern of the fragile site was investigated in 271 offspring of 58 carrier women. At least 30% of the carriers were mildly mentally retarded with most expressing the fragile site. Various other investigations, such as measurements of testes, speech, verbal and IQ evaluations and hormone studies were done on several affected males. No fragile site could be demonstrated in 57 unselected autistic children. The results of this programme show that this syndrome is a common cause of mental retardation and that prevention of mental retardation is possible if all the involved families could be identified.

The incidence of cleft lip and palate in the Western Cape.

The incidence of cleft lip and palate in the Western Cape was studied using data from two cleft palate centres and from all plastic surgeons in practice in the area. A high incidence was found among coloureds, while the incidences among whites and blacks were similar to figures reported from other countries.

A multidisciplinary diagnostic/genetic study on the 105 patients with mental retardation of the E.S. Le Grange School.

A comprehensive genetic/diagnostic survey was undertaken at a special school for the mentally retarded involving 105 patients. Cytogenetic, biochemical and clinical investigations were undertaken to establish the contribution of the genetic factors to the problem of mental retardation. Apart from obtaining information about specific children, identifying families at risk, and providing genetic counselling in nearly 50% of cases, data was obtained which could be compared with other similar surveys. According to the aetiological groupings of the patients, 6.7% could be attributed to perinatal damage, 17.1% to chromosomal defects, 4.8% to biochemical disorders, 5.7% to other genetic causes, 12.4% to other prenatal damage, 1.9% to infections, and 51.4% to unknown causes. No individual with the marker X syndrome was found in this group.

Biochemical evidence for clinically diagnosed adrenoleucodystrophy in two brothers.

Adrenoleucodystrophy (ALD) is a rare, X-linked inherited disease affecting the central nervous system. The clinical findings overlap those of other related progressive neurological diseases and complicate the diagnosis. In this article biochemical analyses of the very-long-chain fatty acid distribution in specimens obtained from 2 related patients clinically diagnosed as having ALD, which unequivocally confirmed the diagnosis, are described. Analyses of the long-chain fatty acids were performed on postmortem brain tissue samples from the one patient. In the other, who is in the terminal phase of the disease, the long-chain fatty acids were analysed in plasma, erythrocytes and fibroblasts from tissue culture. The limitations of the different analyses for biochemical identification of ALD are discussed.

Maternal serum alpha-fetoprotein screening in Natal. Results of over 12 000 tests.

Mass screening of maternal serum alpha-fetoprotein levels for the prenatal detection of fetuses with neural tube defects (NTDs) was introduced in Natal during 1979. From then until 31 October 1982, 12318 pregnancies were monitored and 16 fetuses with NTDs identified. A further 7 abnormal fetuses, 3 with defects other than of the neural tube, were encountered. It is shown that the screening process is reliable and that it does not generate much additional work for ultrasonographers or other laboratories. Few problems related to the management of the screening programme were met; they are discussed with particular reference to the role of ultrasonography.

A familial paracentric inversion: a short review of the current status.

We present here a familial case of a paracentric inversion in man with a short review of the literature. A paracentric inversion of chromosome 10(q11q26) was found in the amniocytes drawn for advanced maternal age. The presence of the inversion was investigated in 35 family members in three generations. No recombinants were recognized. The significance of these data for appropriate genetic counselling and possible reproductive risks is discussed.