Data from subjects receiving intrathecal laronidase for cervical spinal stenosis due to mucopolysaccharidosis type I

Peer reviewe

Schimke immunoosseous dysplasia: defining skeletal features

Schimke immunoosseous dysplasia (SIOD) is an autosomal recessive multisystem disorder characterized by prominent spondyloepiphyseal dysplasia, T cell deficiency, and focal segmental glomerulosclerosis. Biallelic mutations in swi/snf-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1 (SMARCAL1) are the only identified cause of SIOD, but approximately half of patients referred for molecular studies do not have detectable mutations in SMARCAL1. We hypothesized that skeletal features distinguish between those with or without SMARCAL1 mutations. Therefore, we analyzed the skeletal radiographs of 22 patients with and 11 without detectable SMARCAL1 mutations. We found that patients with SMARCAL1 mutations have a spondyloepiphyseal dysplasia (SED) essentially limited to the spine, pelvis, capital femoral epiphyses, and possibly the sella turcica, whereas the hands and other long bones are basically normal. Additionally, we found that several of the adolescent and young adult patients developed osteoporosis and coxarthrosis. Of the 11 patients without detectable SMARCAL1 mutations, seven had a SED indistinguishable from patients with SMARCAL1 mutations. We conclude therefore that SED is a feature of patients with SMARCAL1 mutations and that skeletal features do not distinguish who of those with SED have SMARCAL1 mutations

Increased mortality in cartilage-hair hypoplasia

BACKGROUND—Cartilage-hair hypoplasia (CHH) is an autosomal recessive chondrodysplasia with severe growth failure and impaired immunity. Impaired immunity may result in increased mortality.
AIMS—To follow a cohort of 120 CHH patients for mortality from 1971 to 1995.
METHODS—The overall and cause specific disease mortality rates in patients with CHH, and the disease mortality rate in 194 parents and 158 non-affected sibs were compared with the national rates.
RESULTS—During follow up seven disease related deaths were observed versus 0.8 expected (standardised mortality ratio 9.3, 95% confidence interval 3.7 to 19). In most cases, the deaths were confined to the younger age groups and associated with defective immunity. The mortality of the parents and the non-affected sibs was similar to that in the general population.
CONCLUSION—The study confirms increased mortality in patients with CHH attributable to defective immunity, especially in children.