C1orf194 deficiency leads to incomplete early embryonic lethality and dominant intermediate Charcot-Marie-Tooth disease in a knockout mouse model.

Charcot-Marie-Tooth (CMT) disease is the most common inherited peripheral neuropathy and shows clinical and genetic heterogeneity. Mutations in C1orf194 encoding a Ca2+ regulator in neurons and Schwann cells have been reported previously by us to cause CMT disease. In here, we further investigated the function and pathogenic mechanism of C1or194 by generating C1orf194 knockout (KO) mice. Homozygous mutants of C1orf194 mice exhibited incomplete embryonic lethality, characterized by differentiation abnormalities and stillbirth on embryonic days 7.5-15.5. Heterozygous and surviving homozygous C1orf194 KO mice developed motor and sensory defects at the age of 4 months. Electrophysiologic recordings showed decreased compound muscle action potential and motor nerve conduction velocity in the sciatic nerve of C1orf194-deficient mice as a pathologic feature of dominant intermediate-type CMT. Transmission electron microscopy analysis revealed demyelination and axonal atrophy in the sciatic nerve as well as swelling and loss of mitochondrial matrix and other abnormalities in axons and Schwann cells. A histopathologic examination showed a loss of motor neurons in the anterior horn of the spinal cord and muscle atrophy. Shorter internodal length between nodes of Ranvier and Schmidt-Lanterman incisures was detected in the sciatic nerve of affected animals. These results indicate that C1orf194 KO mice can serve as an animal model of CMT with a severe dominant intermediate CMT phenotype that can be used to investigate the molecular mechanisms of the disease and evaluate the efficacy of therapeutic strategies.

Prevalence, Mortality, and Cause of Death in Charcot-Marie-Tooth Disease in Korea: A Nationwide, Population-Based Study.

BACKGROUND: Charcot-Marie-Tooth disease (CMT) is a group of clinically and genetically heterogeneous disorders that primarily affect the peripheral nervous system. Epidemiological studies of CMT have not yet been performed in Korea. OBJECTIVES: This study was performed to estimate the prevalence of CMT in Korea and the socioeconomic status, mortality, and causes of death of Korean patients with CMT. METHODS: Data on patients with CMT were obtained from the rare intractable disease registry and the National Health Insurance Service for the years 2005-2018. RESULTS: During the study period, 2,885 CMT patients were enrolled. The prevalence per 100,000 persons in 2018 was 5.2 (6.1 for men and 4.4 for women), peaking at ages 15-39 years, with almost twice as many men (n = 714) as women (n = 402) in this age group. Of the CMT patients, 226 (7.8%) were receiving medical aid, a public assistance program targeting poor individuals, at the time of diagnosis and 253 (8.8%) at last follow-up or death. From 2005 to 2017, 170 patients died, including 118 men and 52 women. The standardized mortality ratio (SMR) was 1.57 (95% CI 1.34-1.83) for all patients and did not differ in men and women. Age-specific SMR was highest in patients aged under 9 years, gradually declining thereafter. Neurologic disease as a cause of death was significantly more frequent in CMT patients than in the general population. CONCLUSIONS: This was the first nationwide epidemiologic study of CMT patients in Korea. This study confirmed the characteristics associated with the prevalence of and mortality from CMT by age and is the first to report the socioeconomic status and causes of death of CMT patients.

The impact of comorbidities on inpatient Charcot neuroarthropathy cost and utilization.

AIMS: The purpose of this study was to portray the impact of comorbidities on inpatient cost and utilization in Charcot neuroarthropathy (CN) patients. METHODS: Two cohorts, CN and diabetic peripheral neuropathy (DPN), were identified by ICD-9 codes in the California Office for Statewide Health Planning and Development 2009-2012 public patient discharge files. DPN and CN costs and length of stay (LOS) were compared adjusting for the number of chronic conditions. The impact of the Elixhauser comorbidity measures and other comorbidities on costs and LOS in CN subjects was evaluated. RESULTS: CN was associated with 17.2% higher costs and 1.4 days longer LOS compared to DPN alone. Adjusting for 0.71 additional chronic conditions in CN patients accounted for 79.8% of variance and estimated a 13.9% cost difference between cohorts. Subjects averaged 4.5 Elixhauser comorbidities with higher scores corresponding to increased cost, LOS, and inpatient mortality. Other diabetic foot risk factors demonstrated that foot ulcers, foot infections, and osteomyelitis had significantly higher costs. Patients with foot ulcers, osteomyelitis, and depression had significantly increased LOS. CONCLUSIONS: Systemic and local comorbidities significantly impact the cost, utilization, and inpatient mortality in inpatient management of Charcot foot.

Hereditary ataxias: epidemiological aspects.

Hereditary ataxias, hereditary spastic paraplegia and Charcot-Marie-Tooth syndrome (HA) are chronic progressive neurological diseases. Epidemiologic studies of these disorders are few. In a geographically well-defined Danish population, we present incidence rates, cumulated incidence rates and prevalence for patients with HA based on modern continuous-time survival analysis techniques. From these, prevalence has been estimated to be 6.06 per 10(5) in the 10 to 50-year-old population. Combined risk of HA was found to be 0.16% for women and 0.20% for men up to their 51st birthday.