Genetic screening in kidney transplant candidates.

BACKGROUND

The origin of chronic kidney disease (CKD) remains unknown in ≈16% of patients at the time of renal replacement therapy. The aim of this study was to assess the proportion of monogenic kidney diseases in kidney transplant candidates with kidney disease of unknown cause.

METHODS

Transplant candidates, referred to a nephrogenetic outpatient clinic, had a molecular investigation and were included if they met the following inclusion criteria: absence of diagnosis (including presumed hypertensive nephropathy or vascular or focal segmental glomerulosclerosis lesions) and a glomerular filtration rate <30 ml/min/1.73 m2 before 50 years of age and/or renal morphology abnormality (including renal hypotrophy, cysts and congenital anomalies of the kidney and urinary tract) and/or extrarenal involvement and/or family history of CKD.

RESULTS

Eighty-nine patients were evaluated at the nephrogenetic consultation and 84 patients met the inclusion criteria and were tested and included. Half had a family history of CKD. Almost half of the patients (46.4%) had a morphological abnormality of the kidney. Twenty-eight (33.3%) had been biopsied: 21% had focal and segmental hyalinosis lesions and 25% had chronic interstitial nephropathy. Thirty patients (36%) had a positive genetic diagnosis. Of these, 9/30 (30%) had APOL1 high-risk alleles and 21/30 (70%) had monogenic nephropathy. Patients with a positive genetic diagnosis were significantly more likely to have a family history of kidney disease (70% versus 37%; P = .004).

CONCLUSIONS

Genetic testing enables a diagnosis to be established in 36% of patients, allowing genetic counselling and may help potential living donor evaluations.