1. Pedigree of a mixed Type (I/III) cystinuria family
Pedigree of a mixed Type (I/III) cystinuria family. Squares denote males, circles denote females. White symbols denote normal individuals (N/N) with a silent urinary phenotype. Black symbols denote the compound heterozygote individuals (i.e., III/I). Number under individual symbols represent the haplotypes given by these markers: D2S119 and the SLC3A1 M467T mutation (+, presence of the mutation; −, absence of the mutation) for the rBAT locus (Type I), and D19S225 and D19S425 for the 19q cystinuria locus (Type III). Amino acid excretion values (μmol/g of creatinine) for cystine (CssC), arginine (Arg), lysine (lys), and ornithine (Orn) in the family members are displayed below. Range of values for silent carriers are (μmol/g of creatinine): CssC (20 to 176), Lys (38 to 445); Arg (10 to 55) and Orn (8 to 48) (data taken from Calonge et al.67 ). The two affected sisters in this family carry the M467T mutation; both have passed it on to their progeny. In the third generation, the son (black and white symbol) of one sister shows excretion values higher than normal, suggesting that he has inherited the 19q haplotype corresponding to a mutated allele. Then, there is either an interaction between alleles on chromosome 2 and alleles on chromosome 19, which gives intermediate cystinuria phenotype, or a second unidentified SLC3A1 mutation has been transmitted along with M467T and the 19q locus mutation. In the latter case, it would not be necessary to postulate an interaction between SLC3A1 and the SLC7A9 locus gene products.
Source: Cystinuria, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: November 15, 2017
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