Eight cases of congenital achromatopsia with amblyopia in two pedigrees from Northern Sweden

Two families from northern Sweden with a total of 8 patients with typical symptoms of congenital achromatopsia with amblyopia were studied. In one of the families 4 affected children (3 brothers and 1 sister) also showed pallor of the optic discs and marked astigmatism. The transmission of the disease was consistent with an autosomal recessive inheritance in both families. The study confirmed that complete and incomplete achromatopsia might be different expressions of the same gene. Six out or 13 near relatives of the achromatic patients showed minor colour vision defects, suggesting a tendency towards heterozygotic manifestation of the gene.