ADAMTSL2 mutations determine the phenotypic severity in geleophysic dysplasia.

Geleophysic dysplasia-1 (GD1) is an autosomal recessive disorder caused by ADAMTS-like 2 (ADAMTSL2) variants. It is characterized by distinctive facial features, limited joint mobility, short stature, brachydactyly, and life-threatening cardiorespiratory complications. The clinical spectrum spans from perinatal lethality to milder adult phenotypes. We developed and characterized cellular and mouse models, to replicate the genetic profile of a patient who is compound heterozygous for 2 ADAMTSL2 variants, namely p.R61H and p.A165T. The impairment of ADAMTSL2 secretion was observed in both variants, but p.A165T exhibited a more severe impact. Mice carrying different allelic combinations revealed a spectrum of phenotypic severity, from lethality in knockout homozygotes to mild growth impairment observed in adult p.R61H homozygotes. Homozygous and hemizygous p.A165T mice survived but displayed severe respiratory and cardiac dysfunction. The respiratory dysfunction mainly affected the expiration phase, and some of these animals had microscopic post-obstructive pneumonia. Echocardiograms and MRI studies revealed a significant systolic dysfunction, accompanied by a reduction of the aortic root size. Histology verified the presence of hypertrophic cardiomyopathy with myocyte hypertrophy, chondroid metaplasia, and mild interstitial fibrosis. This study revealed a substantial correlation between the degree of impaired ADAMTSL2 secretion and the severity of the observed phenotype in GD1.

Adeno-associated virus-mediated gene therapy in a patient with Canavan disease using dual routes of administration and immune modulation.

Gene replacement therapy is a rational therapeutic strategy and clinical intervention for neurodegenerative disorders like Canavan disease, a leukodystrophy caused by biallelic mutations in the aspartoacylase (ASPA) gene. We aimed to investigate whether simultaneous intravenous (i.v.) and intracerebroventricular (i.c.v.) administration of rAAV9-CB6-ASPA provides a safe and effective therapeutic strategy in an open-label, individual-patient, expanded-access trial for Canavan disease. Immunomodulation was given prophylactically prior to adeno-associated virus (AAV) treatment to prevent an immune response to ASPA or the vector capsid. The patient served as his own control, and change from baseline was assessed by clinical pathology tests, vector genomes in the blood, antibodies against ASPA and AAV capsids, levels of cerebrospinal fluid (CSF) N-acetylaspartate (NAA), brain water content and morphology, clinical status, and motor function tests. Two years post treatment, the patient's white matter myelination had increased, motor function was improved, and he remained free of typical severe epilepsy. NAA level was reduced at 3 months and remained stable up to 4 years post treatment. Immunomodulation prior to AAV exposure enables repeat dosing and has prevented an anti-transgene immune response. Dual-route administration of gene therapy may improve treatment outcomes.

Causes of death in 184 patients with type 1 Gaucher disease from the United States who were never treated with enzyme replacement therapy.

Treatment for type 1 Gaucher disease (GD1) decreases morbidity from hematological cytopenias, hepatosplenomegaly and bone complications. Consequently, untreated symptomatic patients for study of late outcomes are hard to find. We identified 184 untreated GD1 patients (67.4% Ashkenazi; splenectomy 51.1%) who died between 1950 and 2010. Here, we report confirmed causes of death for these patients compared with the overall US population. Median age of death 66years (2-97years); causes of death (COD) with a high proportional mortality rate (PMR) included malignancies (PMR 1.57), suicide/drug overdose (PMR 3.86), liver disease (PMR 4.76) and septicemia (PMR 9.22). PMRs for CNS/gastrointestinal bleeding, pulmonary hypertension, post-splenectomy complications and Parkinsonism were also increased. PMR for heart disease (0.33) was significantly decreased. Average age at death was normal for heart disease, septicemia, suicide, and malignancies but younger for liver disease and Parkinsonism. COD more prevalent in splenectomy patients included liver disease, septicemia, pulmonary hypertension and GI bleeding. With timely diagnosis, improved risk assessment and obsolescence of splenectomy, GD1-associated malignancies, liver disease, septicemia, pulmonary hypertension, suicide and drug dependency may decrease with early institution of appropriate treatment. Our population of untreated patients is a valuable historical control for studies of the effect of GD1 treatment on premature mortality.