Phenotypic characterization of a pediatric cohort with cystinuria and usefulness of newborn screening.

BACKGROUND: Cystinuria is an inherited metabolic disease involving the defective transport of cystine and the dibasic amino acids in the renal proximal tubules that causes the formation of stones in the urinary system. In our regional child health program, cystinuria is included in newborn metabolic screening. Our objectives are the phenotypic characterization of our cystinuric pediatric cohort and to present our experience in neonatal cystinuria screening. METHODS: The study of clinical cases of pediatric patients diagnosed with cystinuria over a period of 32 years. All patients were studied at demographic, clinical, laboratory, radiological, and therapeutic levels. RESULTS: We diagnosed 86 pediatric patients with cystinuria; 36% of them had the homozygous biochemical phenotype. 95.3% of the patients were detected by neonatal metabolic screening. We performed urine biochemical analyses of parents with additional diagnoses of 63 adult patients. The mean follow-up time was 16.8 ± 8.5 years. 11.6% of patients developed one or more episodes of urinary tract infection during that period. Chronic kidney disease, proteinuria, and hypertension were uncommon (1.2%). 10.5% developed kidney stones at the mean age of presentation of 7.78 ± 7.6 years; 33% were recurrent. The risk of developing lithiasis was higher for homozygous biochemical-phenotype patients. Hypercalciuria was a significant risk factor in the development of lithiasis. CONCLUSIONS: Our clinical data suggest that diagnosing cystinuria through neonatal screening could be a useful strategy for the detection of presymptomatic cases, in order to establish preventive measures, as well as for the detection of relatives at risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

The Castilian Spanish version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR).

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Castilian Spanish language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the three Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability and construct validity (convergent and discriminant validity). A total of 526 JIA patients (8.6% systemic, 49.4% oligoarticular, 18.2% RF negative polyarthritis, 23.8% other categories) and 78 healthy children, were enrolled in six centres. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the Castilian Spanish version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practise and clinical research.