CLINICAL QUIZ An infant presenting with a non-functional kidney on dimercaptosuccinic acid scan: question Neamatollah Ataei & Abbas Madani & Seyed Taher Esfahani & Alireza Sina & Abdolmohammad Kajbafzadeh & Maryam Monajemzadeh & Fatemeh Ataei Received: 26 September 2008 / Revised: 11 March 2009 / Accepted: 14 April 2009 / Published online: 30 June 2009 # IPNA 2009 Case summary A 6.5-month-old girl was hospitalized because of acute pyelonephritis (APN). She was born by cesarean section to a 27-year-old mother and a 33-year-old father, at term and as the second child, after a normal pregnancy. Her weight was 3,000 g, length 49 cm and head circumference (Hc) 32 cm. She was fed breast milk, without regular formula, and had not been given milk or formula imported from other countries. Her healthy parents were third cousins. She had one sibling aged 8 years. The patient had no family history of renal tumour or of any syndrome associated with renal tumour. The paternal history was positive for several episodes of sponta- neous stone passage. Analysis of a stone that her father had passed previously had shown calcium oxalate, but he was not specifically investigated. All immunizations were up to date, and growth and development were within normal ranges. Physical examination revealed unilateral strabismus. Exam- ination by an ophthalmologist showed left esotropia. Examination of the lens, iris, and retina resulted in normal findings. The esotropia had been noted before she was 6 months old. Other systemic examinations did not reveal any other abnormality. The infant was well until 3 days before admission, when fever developed. Laboratory examina- tions, including complete blood count, serum electrolytes, bicarbonate, blood urea nitrogen, creatinine, and liver enzymes, gave normal results on first admission. Urine calcium-to-creatinine ratio in three occasional tests was higher than 0.8. The highest ratio of urinary solutes and creatinine was as follows: oxalate/creatinine 1.94 mg/mg (normal<0.08 mg/mg) and uric acid/creatinine 1.1 mg/mg (normal<1.0 mg/mg). Urinary pH was 5.5, and specific Pediatr Nephrol (2010) 25:253–255 DOI 10.1007/s00467-009-1209-7 Fig. 1 The first DMSA scan shows mild decreased cortical function in the upper poles of both kidneys The answer to this question can be found at http://dx.doi.org/10.1007/ s00467-009-1210-1. N. Ataei (*) : A. Madani : S. T. Esfahani : F. Ataei Department of Pediatric Nephrology, Children’ s Hospital Medical Center, School of Medicine, Tehran University of Medical Sciences, Dr. Gharib St. Azadi Avenue, 14194 Tehran, Iran e-mail: ataiinem@sina.tums.ac.ir A. Sina : A. Kajbafzadeh Department of Pediatric Urology, Children’ s Hospital Medical Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran M. Monajemzadeh Department of Pediatric Pathology, Children’ s Hospital Medical Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran