In Finland a nationwide screening programme for congenital hypothyroidism (CHT) has operated since 1980 with complete coverage. Among the total of 307,000 newborns screened, the incidence per 100,000 was 24.6 for thyroid dysgenesis and 4.0 for dyshormonogenesis. We conclude that, when screening is based on cord serum TSH, the false-positive results are caused mainly by difficult delivery. The most important factors associated with dyshormonogenesis were CHT in the family, origin from a geographic risk area, and origin of both mother and father from the same community. These reflect the autosomal recessive inheritance. The risk factors for dysgenesis were female gender, CHT in the family, birth in a geographic risk area, and birth during a risk period of the year.
Aspartylglycosaminuria is an autosomal recessive disorder of glycoprotein catabolism, characterized by presence of aspartyglycosamine in the urine, progressive mental retardation, coarse face, impaired speech and motor functions, and signs of involvement of connective tissue and skeleton. In infancy, clinical symptoms are mild or absent. Vacuolized lymphocytes are often found in the blood and bone marrow. The disease appears unusually common in Finland.
Patients with autoimmune polyendocrine syndrome type I (APS I) have autoantibodies against the enzyme aromatic L-amino acid decarboxylase (AADC) of pancreatic beta-cells. The aim of the present study was to investigate the presence of anti-AADC antibodies in a large cohort of patients with APS I, and in patients with isolated insulin-dependent diabetes mellitus (IDDM). We found autoantibodies against AADC in 35 of 69 patients (51%) with APS I but in none of 138 patients with isolated IDDM or 91 healthy controls. Among the patients with APS I, anti-AADC antibodies were more often found in those with hepatitis (11/12, 92%), than in those without hepatitis (24/57, 42%) (P = 0.003). Similarly, of 15 patients with vitiligo, 12 (80%) had anti-AADC antibodies, compared with 23/54 (43%) without vitiligo (P = 0.021). Of the 9 APS I patients with IDDM, 5 had antibodies against both AADC and glutamate decarboxylase, 2 against AADC only, and 2 against glutamate decarboxylase only. Interestingly, AADC is present in relatively large amounts in the liver, where its function is unknown. Thus, an autoimmune reactivity against AADC may be involved in the pathogenesis of autoimmune chronic active hepatitis and vitiligo in APS I patients, whereas the role of AADC in the development of IDDM in these patients remains to be determined.
The cranio-facial and dental features were studied by means of roentgencephalometry and anthropometry in 24 patients with cartilage-hair-hypoplasia. Data pertaining to the cranial base were considered indicative of subnormal growth in some of the cranial synchondroses. The width of the neurocranium was slightly below the values of the controls, whereas neurocranial length and circumference appeared unaffected. Facial height was larger than in the controls and facial index values were high. The chin was receding, but the other values of facial depth were relatively large. No abnormalities were observed in tooth morphology, dental age, or dental occlusion. The neurocranial morphology in CHH and achondroplasia show some similarities; the skull base, however, is clearly less bent in the CHH-syndrome. This, together with the virtually normal face and dentition in CHH-patients, is, perhaps, of differential diagnostic value.