Figure 1. Ultrasonographic findings in two families with CAKUT and localization of newly identified mutations in SRGAP1 and SLIT2 cDNAs and proteins.

(A) Renal ultrasonography of individual A4732-21 at age 6 months (SRGAP1 mutation) showing absence of renal tissue on the right side (black arrow-head) at the expected location adjacent to the liver (Li). The left kidney (K) shows compensatory hypertrophy. Prenatally, right multicystic dysplastic kidney (MCDK) was diagnosed (not shown).

(B) Renal ultrasonography of the patient’s mother (SRGAP1 mutation) showing separation of the central echogenic complex in the right kidney (white arrow-head) indicating a non-obstructive duplex kidney. The left kidney is normal.

(C) MCDK on the right side in individual A4736-21 (SLIT2 mutation) at age 3 months (white arrow-heads denote two large cysts).

(D) In the same individual, at age 2.5 years, no renal tissue was detectable on ultrasound on the right (black arrow-head), indicating complete involution of the MCDK. The left kidney (K) shows compensatory hypertrophy.

(E) Exon structure of human SRGAP1 cDNA. The position of the start codon (ATG) and stop codon (TGA) are indicated.

(F) Domain structure of the SRGAP1 protein.

(G) Mutations detected in SRGAP1 in two families with CAKUT (family identifiers are underlined) are depicted as black arrows indicating their positions in relation to exons and protein domains (see also Table 1).

(H) Exon structure of human SLIT2 cDNA.

(I) Domain structure of SLIT2.

(J) Mutations of SLIT2 detected in three unrelated individuals with CAKUT (see also Table 1).

aa, amino acids; bp, base pairs; CT, C-terminal cysteine knot domain; EGF, epidermal growth factor-like domain; FCH, Fes/CIP4 homology domain; IF-BAR, inverse F-BAR domain; K, kidney; LamG, laminin G domain; L, left; Li, liver; LRR, leucin-rich repeat domain; R, right; RhoGAP, GTPase-activator protein for Rho-like GTPases domain; SH3, Src homology 3 domain.