遺伝性周期性四肢麻痺

Andersen-Tawil syndrome (ATS) is a rare, hereditary channelopathy characterized by periodic paralysis, cardiac arrhythmias, and sometimes developmental anomalies. No association with hematologic malignancies has previously been reported. We describe the case of a 27-year-old man with genetically confirmed Type 1 ATS who developed T-cell acute lymphoblastic leukemia. He was treated according to the GRAALL-2014 protocol and achieved sustained complete molecular remission without allogeneic transplantation after 3.5 years of follow-up. Management required careful adaptation to mitigate ATS-related risks. Specifically, QT-prolonging and neurotoxic agents were avoided or substituted, glucose infusions were minimized, and acetazolamide was introduced early. Despite exposure to high-dose corticosteroids and anthracyclines, only moderate, self-limited paralytic episodes occurred during intensive phases. During maintenance, ventricular ectopy and QT prolongation prompted chemotherapy dose adjustments and beta-blocker therapy, leading to rapid normalization. This case highlights the feasibility of delivering intensive chemotherapy in ATS with tailored supportive care. Although likely coincidental, this unprecedented association raises questions about potential links between ion channel dysfunction and leukemogenesis.

Reliable pre-implantation sex determination and genetic screening enables informed embryo transfer decisions in equine breeding while avoiding later interventions. We developed a streamlined workflow that couples rapid whole genome amplification (WGA) with a multiplex real-time PCR targeting ETSTY5 as a Y-specific marker and UBC as an autosomal control. On purified equine DNA, sex was correctly assigned down to 10 pg gDNA and to a single fibroblast cell. Direct testing of embryo biopsies without WGA yielded inconsistent results, whereas introducing a short WGA step produced tight allelic-discrimination clusters and 100% diagnostic calls, including in cloned embryos of known sex. The same WGA product supported targeted genotyping for inherited disease screening of hyperkalemic periodic paralysis (HYPP) and hereditary equine regional dermal asthenia (HERDA) alleles. This WGA plus real-time PCR pipeline supports robust and practical embryo sexing and targeted pre-implantation genetic diagnostics within in vitro produced (IVP) equine embryo and embryo transfer workflows.

Hypokalemic periodic paralysis (HypoPP) occurs in calcium and sodium ion channelopathy, which is a rare presentation following certain triggers. This typically hereditary condition leads to episodic acute muscle weakness associated with hypokalemia, which can later present as permanent weakness. This article presents the case of a 37-year-old male who developed bilateral lower limb weakness associated with severe hypokalemia following intramuscular administration of 8 mg dexamethasone. HypoPP, though not common, should be evaluated in patients following treatment with glucocorticoids. These patients present with typical symptoms that can be managed accordingly.

Periodic paralysis is a rare genetic disorder characterized by recurrent episodes of sudden skeletal muscle weakness. Various factors can trigger this condition, including cold temperatures, abnormal potassium levels, physical activity, and consumption of certain foods. Periodic paralysis is considered benign and usually manifests as muscle weakness. Adult patients with hypokalemic periodic paralysis often experience symptoms such as myalgia and fatigue, whereas myalgia and fatigue are less common in children. We encountered a pediatric patient with hypokalemic periodic paralysis who presented with weakness, general fatigue, and widespread myalgia. The patient was a girl ten years and six months old, admitted to our hospital with generalized muscle weakness after exercise. Her maternal relatives exhibited similar symptoms, including weakness. The patient had hypokalemia but normal thyroid hormone levels. After her serum potassium level was corrected with infusion, her trunk strength and her symptoms resolved. Genetic testing revealed a mutation in CACNA1S, leading to a diagnosis of hereditary hypokalemic periodic paralysis. Occasionally, she experienced persistent general fatigue and widespread pain in her neck, shoulders, arms, lower back, and legs without paralysis or hypokalemia for several days. In conclusion, adult patients with periodic hypokalemic paralysis often experience myalgia and fatigue. Although myalgia and fatigue are rare in pediatric patients, periodic paralysis should still be considered in the differential diagnosis, even in children who show symptoms of muscle pain and fatigue without actual muscle weakness.

BACKGROUND: Paresis and paralysis are often alarming symptoms of a stroke or spinal cord injury and are typically associated with neurological disorders. However, several rare conditions, including myopathies and neuropathies, can also cause paralysis. Due to their low incidence, these diseases are often overlooked, resulting in prolonged diagnostic delays and delayed treatment. CASE PRESENTATION: Here, we present the case of a 26-year-old German Caucasian male carpenter who was admitted to the neurological emergency department with acute tetraplegia. On admission, his potassium level was critically low but returned to normal levels after oral potassium supplementation. He was discharged symptom-free with a diagnosis of hypokalaemic paralysis of unclear origin. However, after he experienced a second episode approximately 1.5 years later, we performed genetic analysis and identified an R528H CACNA1S mutation as the underlying cause of hypokalaemic periodic paralysis. Further genealogical testing revealed that his asymptomatic mother and maternal grandmother were the carriers of the mutation. A decade after his initial presentation, the patient continues to manage episodes of muscle weakness effectively with oral potassium supplementation, avoiding hospitalization. CONCLUSION: This case highlights the importance of considering rare diseases in the differential diagnosis when common causes remain unconfirmed, emphasizing the need for timely genetic testing to facilitate an early precise diagnosis and appropriate management. LEARNING POINTS: CACNA1S mutations should be considered in patients with recurrent episodes of muscle weakness or paralysis accompanied by hypokalaemia, especially if there is a family history of similar symptoms.