Fig. 1

Mutation analysis by direct DNA sequencing. a Family tree. The arrow indicates our proband. Both siblings carried compound heterozygous mutations; the point mutation at position bp 421 (c.421C > T) leads to the substitution of arginine to stop at amino acid position 141 (p.R141X), and the base change from G to A at the first position in intron 7 (c.1200 + 1G > A or IVS7 + 1G > A). The father is heterozygous for the c.1200 + 1G > A mutation and the mother is heterozygous for p.R141X. b Electropherograms of the patient and a healthy control