Comparison of conventional and non-invasive techniques for the early identification of diabetic neuropathy in children and adolescents with type 1 diabetes.

BACKGROUND: Neuropathy is an important complication and contributes to the morbidity of diabetes mellitus. The availability of simple and non-invasive tests for screening of early diabetic neuropathy (DN) in children with diabetes may prevent further progression of this complication. The purpose of this study was to compare conventional nerve conduction studies (NCS) with non-invasive techniques, including vibration perception thresholds (VPT) and tactile perception thresholds (TPT) for the detection of DN in children and adolescents with type 1 diabetes. METHODS: Children from the Alberta Children's Hospital Diabetes Clinic with at least 5 yr duration of type 1 diabetes underwent detailed evaluations, including neurologic exam, NCS, VPT, and TPT testing. Information on duration of diabetes, height, and mean glycosylated hemoglobin (A1C) were also collected. Descriptive statistics, including Student's t-test and chi-squared test, were used for analysis. RESULTS: Seventy-three children (mean age of 13.7+/-2.6 yr) completed the study. The mean duration of diabetes was 8.1+/-2.6 yr, and the mean A1C was 9.0+/-1.0%. Forty-two (57%) children had DN based on NCS. Using NCS as a gold standard, the sensitivity and specificity of VPT were 62 and 65%, while the sensitivity and specificity of TPT were 19 and 64%, respectively. CONCLUSIONS: Subclinical DN is common among children and adolescents with type 1 diabetes, and there is a need for better metabolic control in this population. VPT and TPT may not be adequate screening tools for the detection of DN in children.

Autosomal recessive cerebellar hypoplasia in the Hutterite population.

Cerebellar hypoplasia is a rare malformation caused by a variety of etiologies. It usually manifests clinically as non-progressive cerebellar ataxia with or without mental retardation. We further characterize a syndrome of autosomal recessive cerebellar hypoplasia in the Hutterite population, referred to as dysequilibrium syndrome (DES). We reviewed 12 patients (eight females, four males; age range 4 to 33 y) with this syndrome. Patients were examined and underwent a standard set of investigations to characterize better the clinical features, natural history, and neuroimaging of this syndrome. DES is an autosomal recessive disorder with distinct clinical features including global developmental delay, late ambulation (after age 6 y), truncal ataxia, and a static clinical course. Neuroimaging is characterized by hypoplasia of the inferior portion of the cerebellar hemispheres and vermis, and mild simplification of cortical gyri.

Infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1).

Autosomal recessive spinal muscular atrophy with respiratory distress type 1 (SMARD1) is the second anterior horn cell disease in infants in which the genetic defect has been defined. SMARD1 results from mutations in the gene encoding the immunoglobulin micro-binding protein 2 (IGHMBP2) on chromosome 11q13. Our aim was to review the clinical features of 29 infants affected with SMARD1 and report on 26 novel IGHMBP2 mutations. Intrauterine growth retardation, weak cry, and foot deformities were the earliest symptoms of SMARD1. Most patients presented at the age of 1 to 6 months with respiratory distress due to diaphragmatic paralysis and progressive muscle weakness with predominantly distal lower limb muscle involvement. Sensory and autonomic nerves are also affected. Because of the poor prognosis, there is a demand for prenatal diagnosis, and clear diagnostic criteria for infantile SMARD1 are needed. The diagnosis of SMARD1 should be considered in infants with non-5q spinal muscular atrophy, neuropathy, and muscle weakness and/or respiratory distress of unclear cause. Furthermore, consanguineous parents of a child with sudden infant death syndrome should be examined for IGHMBP2 mutations.