Two Novel Variants of the CAPN3 Gene in Chinese Patients with Limb-Girdle Muscular Dystrophy Recessive 1.

INTRODUCTION: Recessive mutations in the CAPN3 gene can lead to limb-girdle muscular dystrophy recessive 1 (LGMD R1). Targeted next-generation sequencing facilitates the discovery of new mutations linked with disease, owing to its ability to selectively enrich specific genomic regions. METHODS: We performed targeted next-generation sequencing of all exons of the CAPN3 gene in 4 patients with sporadic limb-girdle muscular dystrophy (LGMD) and further analyzed the effects of the novel identified variant using various software tools. RESULTS: We found 5 variants in CAPN3 gene in 4 patients, c.82_83insC (insertion mutation) and c.1115+2T>C (splicing mutation) are reported for the first time in CAPN3 (NM_000070.2). The bioinformatics analysis indicated that these two novel variants affected CAPN3 transcription as well as translation. DISCUSSION: Our findings reveal previously unreported splicing mutation and insertion mutation in CAPN3 gene, further expanding the pathogenic gene profile of LGMD.

Miller-Fisher syndrome with positive anti-GD1b and anti-GM1 antibodies combined with multiple autoimmune antibodies: A case report.

RATIONALE: Anti-ganglioside antibodies (AGA) play an essential role in the development of Miller-Fisher syndrome (MFS). The positive rate of ganglioside antibodies was exceptionally high in MFS, especially anti-GQ1b antibodies. However, the presence of other ganglioside antibodies does not exclude MFS. PATIENT CONCERNS: We present a 48-year-old male patient who suddenly developed dizziness, visual rotation, nausea, and vomiting accompanied by unsteady gait and diplopia for 3 days before presentation to our clinic. DIAGNOSES: On physical examination, the patient's right eye could not fully move to the right side and horizontal nystagmus was found. Coordination was also impaired in the upper and lower extremities with dysmetria and dysdiadochokinesia. The electromyography and cerebrospinal fluid examination results were normal. The serum anti-GQlb antibody test results were negative. However, serum anti-GD1b IgM and anti-GM1 IgM antibodies were positive. Meanwhile, the anti-thyroid peroxidase antibody was >600.00 IU/mL (0.00-34.00), and the anti-SS-A/Ro52 antibody was positive. He was diagnosed with MFS. INTERVENTIONS: The patient received IVIg treatment for 5 days (0.4 g/kg/day) from day 2 to day 6 of hospitalization. On the 7th day of admission, the patient was administered intravenous methylprednisolone (500 mg/day), which was gradually reduced. OUTCOMES: The patient's symptoms improved after treatment with immunoglobulins and hormones. LESSONS: We report a case of MFS with positive anti-GD1b and anti-GM1 antibodies combined with multiple autoimmune antibodies. Positive ganglioside antibodies may be used as supporting evidence for the diagnosis; however, the diagnosis of MFS is more dependent on clinical symptoms.

Primary biliary cirrhosis associated with myasthenia gravis after postpartum: a case report.

BACKGROUND: Autoimmune diseases refers to a class of diseases involving abnormal immune response of human body and tissue damage caused by the dysregulation of autoimmune balance or destruction of immune tolerance. Recent research has revealed that the occurrence of autoimmune diseases is influenced by genetic, hormonal, immunological, and environmental factors. As sex hormone levels change obviously during pregnancy and postpartum, the morbidity and recurrence rate of autoimmune diseases increase during this period. CASE PRESENTATION: A 31-year-old Asian woman was admitted to our hospital for myasthenia gravis and treated with methylprednisolone and pyridostigmine bromide 3 months postpartum. Physical examination and laboratory inspection after admission suggested that the patient had primary biliary cirrhosis. Subsequently, azathioprine was added to the treatment, and the symptoms of both diseases were successfully controlled. CONCLUSIONS: This case exhibits a rare condition of myasthenia gravis combined with primary biliary cirrhosis postpartum. Given the fluctuation of the immune status during the postpartum period, combined autoimmune diseases need to be taken into account when patients develop clinical symptoms of an autoimmune disease. Therefore, detailed physical and laboratory examination can help to prevent the missed diagnosis of these diseases.