a detailed description of patients with history of recurrent respiratory infections and progressive renal failure was given 1979 . the case under discussion has various rare features like young age of the patient , associated glomerulopathy causing nephrotic syndrome and normal renal function , which is showing gradual deterioration . normal renal function at the time of diagnosis is known and in one large series published by bhandari et al . an 8-year - old male child presented with a history of facial puffiness and edema of one year duration . he was diagnosed to have nephrotic syndrome and was treated by a local physician with steroids . he did not improve , however , and was referred to this hospital for further management . there was no history of drug ingestion including exposure to mycotoxins or other herbal medicines . patient had stunted growth with moon facies , secondary to steroids and had clinical features of rickets . his investigations revealed hemoglobin of 10 g / dl , blood urea 33 mg / dl and serum creatinine 0.7 mg / dl . he was human immunodeficiency virus non - reactive and hepatitis b surface antigen and hepatitis c virus and 24 h urine protein was 3565 mg / dl . complete urine examination showed 2 + albumin , 4 - 6 red blood cells and granular casts . he was started on cyclophosphamide . however , there was no response even after 6 months . biopsy showed 23 glomeruli , four of whom showed segmental sclerosis [ figure 1 ] . segmental glomerulosclerosis ( thin arrow ) and karyomegaly in tubular cells ( thick arrow ) ( h and e , 400 ) karyomegaly in tubular epithelial cells ( h and e , 400 ) ( a ) segmental sclerosis and tubular atrophy ( periodic acid schiff , 200 ) . ( b ) tubular atrophy and interstitial inflammation ( h and e , 200 ) . ( c ) interstitial fibrosis ( masson 's trichrome , 200 ) immunohistochemical stains for bk virus and cytomegalovirus were negative . he is under regular follow - up and his last creatinine has increased to 1.2 mg / dl . kin is a rare disorder characterized by enlarged tubular epithelial cell nuclei and chronic interstitial nephritis . histologically , presence of interstitial nephritis along with karyomegaly in the tubular epithelial cells is characteristic of this disorder . karyomegalic cells have been identified in various tissues like astrocytes , schwann cells , intestinal smooth muscle and bile duct epithelium . mcculloch et al . , reported kin in three adolescent patients treated with ifosfamide for ewings sarcoma . a familial clustering is known and frequency of human leukocyte antigen ( hla)-a9 and hla - b35 haplotypes suggest the possibility of genetic susceptibility . another genetic defect on chromosome 6 , linked to major histocompatibility complex locus is also suspected . the morphological alterations in renal epithelial cells are thought to be the initial damage caused by either chemicals or viral agents , which in susceptible individuals lead to disruption of cells . immunofluorescence and histological findings are negative in a large series presented by bhandari et al . in contrast our case clinically presented with nephrotic syndrome and also had histological evidence of focal segmental glomerulosclerosis ( fsgs ) . as there is no positive family history or drug history and exposure to toxins , it is important to diagnose this entity as it is a progressive disorder leading to irreversible renal damage . common etiological factors for both these lesions are toxins and drugs , patient on repeated questioning denied any history of drug or herbal medicine intake . there is no history of renal disease in the family and it unlikely to be familial because the chromosomal abnormalities described are different for both . spoendlin et al . , reported four patients who were asymptomatic initially , but later experienced progressive renal failure . this particular case under discussion also initially presented with normal renal function and on follow - up was showing gradual deterioration . we present a rare case of kin who initially presented with normal renal parameters ; interestingly , this patient 's clinical presentation was of nephrotic syndrome whose biopsy also revealed fsgs . hence , we think that the patient has idiopathic fsgs with an incidental kin , which is known to occur sporadically .
karyomegalic interstitial nephritis ( kin ) is a rare form of , progressive chronic interstitial nephritis . 
 we present a case of kin in a child , who was also found to have nephrotic syndrome because of focal segmental glomerulosclerosis on renal biopsy . to our knowledge , this is the first case of kin associated with glomerulopathy .