New insights from the genetic work-up in early onset nephrotic syndrome: report from a registry in western India

BACKGROUND

Eighty-five percent of infants with congenital nephrotic syndrome (CNS) and 66% with infantile NS (INS) are likely to have a monogenic etiology. There exists a significant genetic variability between different regions and ethnic groups. This study aimed to determine the genetic defects in children with CNS and INS by establishing a registry in western India.

METHODS

In this cross-sectional study, pediatric nephrologists from 13 private and government institutions shared relevant clinical data and details of the genetic evaluation of children presenting with NS within the first year of life.

RESULTS

The median age at presentation was 9 months (range 1-23, IQR 3-13 months), history of consanguinity between parents existed in 14 patients (34%), family history of similar illness in 6 (15%), and extra-renal manifestations in 17 (41%). Twenty-five (61%) were confirmed to have a monogenic etiology. NPHS1 gene was the most implicated (9/25) followed by PLCE1 (5/25). There were 12 variants of uncertain significance (VUS) involving 10 genes (10/25, 40%), and no definite genetic abnormality was found in 4 (25%). A re-analysis of these VUS attempted 2-3 years later facilitated reclassification of 7/12 (58%); increasing the diagnostic yield from 61 to 68.2%.

CONCLUSIONS

Consistent with worldwide data, variants in NPHS1 gene were the most common cause of NS in infancy; however, PLCE1 was implicated more frequently in our cohort. NUP93 and COL4A3 were reported in early onset NS for the first time. Reclassification of VUS should be attempted, if feasible, since it may lead to a useful revision of diagnosis.

Acute renal failure secondary to ingestion of ayurvedic medicine containing mercury

Several traditional medicines contain potentially toxic heavy metals. Heavy metal poisoning is not an uncommon cause of renal damage, although the diagnosis can be easily missed. We report a case of chronic ingestion of an ayurvedic medicine containing mercury in a 2-year-old girl, resulting in anuric renal failure due to acute interstitial nephritis.

Does deafness lead to enhancement of visual spatial cognition in children? Negative evidence from deaf nonsigners

This study investigated whether deafness contributes to enhancement of visual spatial cognition independent of knowledge of a sign language. Congenitally deaf school children in India who were born to hearing parents and were not exposed to any sign language, and matched hearing controls, were given a test of digit span and five tests that measured visual spatial skills. The deaf group showed shorter digit span than the hearing group, consistent with previous studies. Deaf and hearing children did not differ in their performance on the visual spatial skills test, suggesting that deafness per se may not be a sufficient factor for enhancement of visual spatial cognition. Early exposure to a sign language and fluent sign skills may be the critical factors that lead to differential development of visual spatial skills in deaf people.