A defective anosmin-1 molecule may also play a role in the development of synkinesia and renal agenesis, which are exclusively seen in the X-linked form of KS.
In addition, the high frequency of unilateral renal aplasia in X-linked Kallmann patients (6 out of 11 males with identified alterations of the KAL gene) should be emphasized.
The high frequency of renal agenesis in this family, in the presence and absence of the KAL-1 mutation, suggests an autosomal dominant or X-linked gene which may independently or co-dependently contribute to renal agenesis.
The phenotype of renal agenesis/dysgenesis strongly indicates the existence of KAL1 gene defects in the genotype of patients with sporadic KS, providing evidence for the X-linked mode of inheritance and offering the opportunity for genetic counseling.