Marvin P. Rozear

Hereditary motor and sensory neuropathy, X‐linked A half century follow‐up

The existence of an X-linked sensorimotor peripheral neuropathy has been debated. We reevaluated the original family, and present data on 13 affected males and 25 obligate or probable heterozygous females, documenting the devastating nature of the disease in the men and the extremely variable degree of clinical involvement in the carriers. Use of DNA probes indicates that the gene lies in the DXYS1-p58-1 region of the X-chromosome.

The National Registry of Veterans with Amyotrophic Lateral Sclerosis

Background: The Department of Veterans Affairs (VA) Cooperative Studies Program has established a National Registry of Veterans with Amyotrophic Lateral Sclerosis (ALS). This article describes the objectives, methods, and sample involved in the registry. Methods: United States military veterans with ALS were identified through national VA electronic medical record databases and nationwide publicity efforts for an enrollment period of 4 1/2 years. Diagnoses were confirmed by medical record reviews. Registrants were asked to participate in a DNA bank. Follow-up telephone interviews are conducted every 6 months to track participants’ health status. Results: As of September 30, 2007, 2,400 veterans had consented to participate in the registry, 2,068 were included after medical record review, 995 were still living and actively participating, and 1,573 consented to participate in the DNA bank. 979 participants had been enrolled in the registry for at least 1 year, 497 for at least 2 years, and 205 for at least 3 years. Fourteen studies have been approved to use registry data for epidemiological, observational, and interventional protocols. Conclusion: This registry has proven to be a successful model for identifying large numbers of patients with a relatively rare disease and enrolling them into multiple studies, including genetic protocols.

Confirmation of a second locus for CMT2 and evidence for additional genetic heterogeneity

ABSTRACTThe Charcot-Marie-Tooth (CMT) neuropathies are a group of disorders exhibiting neurophysical, pathological and genetic heterogeneity. CMT2 is a diagnostic subtype of this group of disorders characterized by variable expression and age-of-onset and normal or slightly diminished nerve conduction velocities. Previously, linkage and heterogeneity had been reported in CMT2 with linked families localizing to chromosome 1p (CMT2A). Recently a second CMT2 locus has been described on chromosome 7 in a single large CMT2 family (CMT2D). We have performed pedigree linkage analysis on 15 CMT2 families (N = 371 individuals, 106 affected family members) and have confirmed linkage to chromosome 7. Furthermore, using both admixture and multipoint linkage analysis we show conclusive evidence for additional heterogeneity within this clinical subtype with evidence of families that exclude linkage to both the CMT2D and CMT2A regions. In addition, unlike the previous report we found no abvious consistend clinical differences between the linked family types.

Factors associated with survival in the National Registry of Veterans with ALS

The clinical course of patients with ALS is highly variable. While the median survival time from symptom onset is 2–4 years, there are reports of survival ranging from less than a year to more than 40 years. Such variability makes planning difficult for patients and physicians, and complicates clinical trial design. We sought to validate previous predictors of survival and search for new ones using a large group of ALS patients in the National Registry of Veterans with ALS. We were especially interested in how various aspects of military service might affect survival. Subjects were those in the National Registry of Veterans with ALS who had probable or definite ALS (according to El Escorial criteria). A multivariable Cox proportional hazard regression model was used to examine variables for statistical association with ventilator-free survival time (determined from date of first diagnosis). Subjects who had not died or started ventilation by 31 October 2006 were censored. Our group of 1085 US military veterans with ALS was primarily male (98%) and white (94%), with mostly sporadic (95%) and extremity-onset (76%) ALS. Symptom onset occurred at a mean age of 59.3 years (60.6 years for diagnosis). Median survival time from symptom onset was 4.7 years (3.3 years from diagnosis). In our multivariable model, older age at diagnosis (HR 1.41 (95% CI 1.27–1.55) per 10-year increase), non-extremity site of onset (HR 1.55 (1.24–1.94)), and past deployment to Vietnam (HR 1.73 (1.36–2.19)) were all associated with shortened survival. A longer time to diagnosis was associated with better survival (HR 0.77 (0.70–0.84) per one year increase in diagnosis time). In this unique cohort of veterans with ALS, traditional factors of reduced survival remained important. In addition, past deployment to Vietnam was found to be associated with shortened survival as well. This finding could be due to a common exposure, a shared characteristic, an unmeasured confounder, or an enrollment bias. More research will be needed to understand the reasons behind this new finding.

Time to diagnosis in the National Registry of Veterans with Amyotrophic Lateral Sclerosis.

Our objective was to determine the interval from symptom onset to diagnosis, and to evaluate associated factors in a cohort of U.S. Veterans with motor neuron diseases. We retrospectively evaluated 1359 patients enrolled in the National Registry of Veterans with Amyotrophic Lateral Sclerosis (ALS). The main outcome measures were time from symptom onset to first diagnosis and to second opinion. Predictor variables included age at symptom onset, year of symptom onset, race, onset site, final diagnosis, number of diagnostic tests performed and clinical sites visited. Median time to first diagnosis was 11 months; median time to second opinion was two months. In a multivariable model, more recent calendar year of symptom onset, younger age, bulbar onset and a diagnosis of ALS versus non-ALS motor neuron disease were all significantly associated with a shorter time to first diagnosis. Later year of symptom onset and white race were significantly associated with a shorter time to second opinion. While the interval from symptom onset to diagnosis, and many of the associated factors are similar between our large cohort of U.S. Veterans with ALS and other smaller published cohorts, we found that the diagnostic interval among U.S. Veterans has significantly decreased over time.