Genotyping is a valuable diagnostic complement to neonatal screening for congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency.

To evaluate genotyping as a diagnostic complement to neonatal screening for congenital adrenal hyperplasia, 91 children who had been diagnosed with this condition between 1986 and 1997 were analyzed for mutations in the steroid 21-hydroxylase gene. Screening levels of 17-hydroxyprogesterone were compared in patients representing different genotypes. Genotyping was performed using allele-specific PCR, the patients were divided into four groups according to the severity of their mutations, and screening results were compared between these groups as well as with 141 values representing false positive samples. The screening levels of 17-hydroxyprogesterone were significantly different in the five groups of samples. Values above 500 nmol/L were clearly associated with the most severe genotypes, whereas conclusions concerning disease severity could not be drawn from individual samples representing lower levels. For example, values around 150-200 nmol/L could be seen in children with all degrees of disease severity and could also constitute false positive samples. We conclude that genotyping is a valuable diagnostic tool and a good complement to neonatal screening, especially in confirming or discarding the diagnosis in cases with slightly elevated 17-hydroxyprogesterone levels. An additional benefit is that it provides information on disease severity, which reduces the risk of overtreatment of mildly affected children.

Early growth is not increased in untreated moderately severe 21-hydroxylase deficiency.

The pretreatment growth of 1 British and 14 Swedish children with late (2-7 years) diagnosis of 21-hydroxylase deficiency (21OHD) was studied. The latter group included all patients diagnosed in Sweden after 1986. Twelve had mutations of the 21-hydroxylase gene that are generally associated with moderately severe ("simple virilizing") forms of 21OHD, one had a severe ("salt-losing") and one a mild ("non-classical") form. The British girl was followed from 4 months of age. She had grossly elevated levels of 17 alpha-hydroxyprogesterone, androstenedione and testosterone in blood, but her parents refused treatment until she was 4 years of age. None of the 15 children showed any significant increase in growth or progress of virilization until after 18 months of age. These observations indicate that growth during the first 1.5 years is not very sensitive to androgens. Thus glucocorticoid replacement during the first year of life should be kept to a minimum to avoid over-treatment.

Mutational spectrum of the steroid 21-hydroxylase gene in Sweden: implications for genetic diagnosis and association with disease manifestation.

We have characterized the disease-causing mutations in the steroid 21-hydroxylase genes of 127 patients with different clinical forms of congenital adrenal hyperplasia, representing 186 unrelated chromosomes. The gene was completely absent on 29.8% of the chromosomes, and this together with the I2 splice (27.7%), I173N (20.8%), V282L (5.4%), and R357W (3.8%) mutations constitute 87.5% of all affected chromosomes. In total, 15 different sequence aberrations combine to form 19 different disease-causing alleles. The results confirm that genotyping is an efficient means of diagnosing steroid 21-hydroxylase deficiency, although special consideration is needed to resolve genotypes when full families are not available. Clinical presentations of the different combinations of mutations indicate that genotyping is reliable for prediction of clinical outcome in patients with 21-hydroxylase deficiency. It is especially helpful in determining whether in utero treatment of affected females is indicated and in classifying the severity of 21-hydroxylase deficiency in children diagnosed through neonatal screening, before symptoms have appeared.

Congenital adrenal hyperplasia in Sweden 1969-1986. Prevalence, symptoms and age at diagnosis.

A retrospective study of all Swedish patients with congenital adrenal hyperplasia (CAH) born 1969-1986, was conducted to elucidate possible benefits of neonatal screening for CAH. Information was obtained about 150 patients (67 male, 83 female). One hundred and forty-three cases were regarded as classical and seven as non-classical (symptoms after 5 years of age or cryptic). All but two (one girl with 11-hydroxylase deficiency and one boy with beta-hydroxysteroid-dehydrogenase deficiency) had 21-hydroxylase deficiency. The prevalence was 1:11,500. Ninety-three patients (48 male, 45 female) displayed salt loss, all before the age of 3 months. Two boys had died and many children had been critically ill during the first weeks of life. The median age at diagnosis for boys in this group was 21 days. Gender assignment was a major problem in 38 of 57 girls with ambiguous genitalia noticed during the first day. Fifteen of these girls were considered to be male for their first 40 days (median), before the CAH diagnosis was established. Patients in whom the first symptom was manifested after the age of one year often showed growth acceleration, which frequently was overlooked. Median diagnostic delay in this group was 17 months. Possible benefits of neonatal screening are: avoidance of a serious salt-loss crisis; earlier diagnosis and correct gender assignment in virilized girls; decreased virilization, growth acceleration and premature pubarche in prepubertal children; and reduced negative consequences for psycho-social development and final height.

Incidence and prevalence of juvenile chronic arthritis: a population survey.

In a population based epidemiological survey of juvenile chronic arthritis (JCA), performed in Western Sweden in 1983, an incidence of 12/100,000 was found. The estimated prevalence was 56/100,000. Subgroup distribution showed a preponderance of mono- and pauciarticular forms. The peak age of onset was between 0 and 4 years of age. Girls predominated over boys in a ratio of 3:2. Overall, 30% were antinuclear antibody (ANA) positive, 9% rheumatoid factor (RF) positive, and eye involvement occurred in 10% of the children. The results suggest differences in population based studies of JCA compared with previously reported hospital based series.

Fanconi's anaemia associated with haemophilia A.

Fanconi's anaemia and haemophilia A are born inherited diseases creating haemostatic defects. The association of these two rare diseases in one patient is described. The patient's haemophilia was studied with a newly developed immunological technique determining the plasma antigen associated with Factor VIII activity, and was found to be a genetic variant of moderately severe haemophilia A. It was not possible to demonstrate a common bone marrow defect or a common immunological or genetical background of the two diseases. The double haemostatic defect created, i.e. Factor VIII deficiency and thrombocytopenia, resulted in only a slight increase in bleeding tendency. A favourable result was obtained with corticosteroid and androgenic treatment.

Granulopoiesis in infantile genetic agranulocytosis. In vitro cloning of marrow cells in agar culture.

A 3-year-old boy and a 2-year-old girl with infantile genetic agranulocytosis have been studied by in vitro cloning of bone marrow cells in agar culture. The patients display a normal concentration of colony forming cells and the morphological maturation is identical with that of control marrow cultured in vitro. The marrow cells of the patients show some degree of auto-stimulation indicating that endogenous production of colony stimulating factor is operating. As an inverse relationship is expected between the peripheral neutrophil count and the percentage of marrow colony forming cells in S-phase a high percentage was expected. On the contrary, we find that the percentage of colony forming cells in S-phase is extremely low indicating a genetic unresponsiveness of granulopoietic precursor cells to feed back regulation in infantile genetic agranulocytosis.