TABLE 1.

Summary of clinical outcomes in patients with a congenital or early-acquired SFK.

References	Total number of patients	Gender (M/F)	Type of patients included	Age (years)	Kidney injury	Kidney length as a predictor of kidney injury
Sanna-Cherchi et al. (2009)	71	52/19	URA or empty renal fossa upon imaging	Mean age 21 (SD 13.6)	20–40% dialysis	NR
Wang et al. (2010)	65	36/29	48 with URA 17 with severe unilateral kidney dysplasia	Mean age 36.7 (SD 13.1)	38.5% reduced GFR (<60 ml/min/1.73 m2) 35.4% proteinuria 3% dialysis 36.9% hypertension	Kidney length < 120 mm five-fold greater risk reduced GFR
Xu et al. (2019)	118	62/56	URA	Median age 32	25.4% reduced GFR (<60 ml/min/1.73 m2) 43% proteinuria 32.2% hypertension	Patients with reduced GFR had a shorter kidney length
Westland et al. (2011, 2013a)	407	265/142	223 congenital SFK (URA or MDCK) 184 early acquired SFK	Mean age 6.4 (SD 5.7) Mean age 9.8 (SD 5.6) Mean age 4.9 (SD 5.4)	6% reduced GFR (<60 ml/min/1.73 m2) 19% proteinuria 26% hypertension	Patients with a smaller SFK had a greater incidence of kidney injury
Marzuillo et al. (2017, 2019)	306	Not specified	Prenatally diagnosed (URA and MCDK)	Mean age of kidney injury onset 8.2 (SD 5.6)	1.3% reduced GFR (<90 ml/min/1.73 m2) 3.6% proteinuria 0.6% hypertension	In 162 of the 306 patients - kidney length < 2-SDS in the neonate period had a greater risk of reduced GFR at 15 years of age irrespective of postnatal kidney hypertrophy
La Scola et al. (2016)	146	95/51	URA, aplasia and MCDK	Median age 2.2 Mean age 5.6 ± (4.4 SD) Mean age 12.2 (3.1 SD)	12% reduced GFR (<90 ml/min/1.73 m2) 4% proteinuria 5% hypertension	Kidney length < 10% expected for a congenital SFK was the strongest predictor of reduced GFR by 10 years of age

NR, not recorded; SD, standard deviation; URA, unilateral renal agenesis; MCDK, multicystic dysplastic kidney; GFR, glomerular filtration rate; eGFR, estimated glomerular filtration rate.