ABSTRACT
Transient receptor potential channel C6 encoded by TRPC6 is involved in slit diaphragm formation in podocytes, and abnormalities of the TRPC6 protein cause various glomerular diseases. The first identified pathogenic variant of TRPC6 was found to cause steroid-resistant nephrotic syndrome that typically developed in adulthood and then slowly led to end-stage renal disease, along with a renal pathology of focal segmental glomerulosclerosis. Here, we report a patient with rapidly progressing infantile nephrotic syndrome and a heterozygous missense TRPC6 variant. The patient, a 2-year-old Japanese boy, developed steroid-resistant nephrotic syndrome at age 11 months. His renal function deteriorated rapidly, and peritoneal dialysis was introduced at age 1 year and 6 months. His renal pathology, obtained at age 1 year and 1 month, was consistent with diffuse mesangial sclerosis (DMS). Clinical exome analysis and custom panel analysis for hereditary renal diseases revealed a reported heterozygous missense variant in TRPC6 (NM_004621.5:c.523C > T:p.Arg175Trp). This is the first report of a patient with a TRPC6-related renal disorder associated with DMS.
Subject(s)
Kidney Diseases/genetics , Nephrotic Syndrome/genetics , Sclerosis/genetics , TRPC6 Cation Channel/genetics , Child, Preschool , Exome/genetics , Genetic Predisposition to Disease , Glomerulosclerosis, Focal Segmental/complications , Glomerulosclerosis, Focal Segmental/diagnostic imaging , Glomerulosclerosis, Focal Segmental/genetics , Glomerulosclerosis, Focal Segmental/pathology , Heterozygote , Humans , Infant , Kidney/diagnostic imaging , Kidney/pathology , Kidney Diseases/complications , Kidney Diseases/diagnostic imaging , Kidney Diseases/pathology , Male , Mutation, Missense/genetics , Nephrotic Syndrome/complications , Nephrotic Syndrome/diagnostic imaging , Nephrotic Syndrome/pathology , Podocytes/metabolism , Podocytes/pathology , Sclerosis/complications , Sclerosis/diagnostic imaging , Sclerosis/pathologyABSTRACT
Human cytomegalovirus (CMV) is the most common cause of infection-related congenital abnormalities in neonates and the leading cause of non-hereditary sensorineural hearing loss in childhood. In addition, the number of low-birth-weight infants has recently increased, especially in Japan, in association with an increasing frequency of postnatal CMV infections transferred through raw breast milk. The increase in the number of congenital CMV and postnatal CMV infections in low-birth-weight infants requires rapid detection at the bedside in order to ensure a correct diagnosis and provide early anti-viral therapy. In this report, a simplified smart amplification (SMAP) method was developed to detect CMV in the urine of neonates. This method does not require DNA extraction, and the DNA amplification procedure is performed under isothermal conditions. Therefore, it takes only 60 min to detect CMV in a urine sample, and CMV DNA was rapidly detectable in symptomatic infants. In brief, this SMAP-based assay provides a simple, rapid and efficient method for detecting human CMV at the bedside.
