青少年起病的成人型糖尿病（MODY）是一类特殊类型糖尿病。MODY10是其中一种较为罕见的类型，与胰岛素基因突变导致胰岛素的合成和分泌障碍有关，大多呈常染色体显性遗传，家族成员中可有不同的临床表现。本文报道1个以低钾性周期性麻痹为主要表现、经全外显子基因检测证实为胰岛素基因突变的MODY10家系，拟通过该病例的诊治体会并结合国内外文献复习，提高临床医生对该特殊类型糖尿病的认识。.

BACKGROUND: Primary periodic paralysis (PPP) is an inherited disorders of ion channel dysfunction characterized by recurrent episodes of flaccid muscle weakness, which can classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. However, PPP is charactered by remarkable clinical and genetic heterogeneity, and the diagnosis of suspected patients is based on the characteristic clinical presentation then confirmed by genetic testing. At present, there are only limited cohort studies on PPP in the Chinese population.
RESULTS: We included 37 patients with a clinical diagnosis of PPP. Eleven (29.7%) patients were tested using a specific gene panel and 26 (70.3%) by the whole-exome sequencing (WES). Twenty-two cases had a genetic variant identified, representing a diagnostic rate of 59.5% (22/37). All the identified mutations were either in the SCN4A or the CACNA1S gene. The overall detection rate was comparable between the panel (54.5%: 6/11) and WES (61.5%: 16/26). The remaining patients unresolved through panel sequencing were further analyzed by WES, without the detection of any mutation. The novel atypical splicing variant c.2020-5G > A affects the normal splicing of the SCN4A mRNA, which was confirmed by minigene splicing assay. Among 21 patients with HypoPP, 15 patients were classified as HypoPP-2 with SCN4A variants, and 6 HypoPP-1 patients had CACNA1S variants.
CONCLUSIONS: Our results suggest that SCN4A alleles are the main cause in our cohort, with the remainder caused by CACNA1S alleles, which are the predominant cause in Europe and the United States. Additionally, this study identified 3 novel SCN4A and 2 novel CACNA1S variants, broadening the mutation spectrum of genes associated with PPP.

The CACNA1S gene encodes the alpha 1 S-subunit of the voltage-gated calcium channel, which is primarily expressed in the skeletal muscle cells. Pathogenic variants of CACNA1S can cause hypokalemic periodic paralysis (HypoPP), malignant hyperthermia susceptibility, and congenital myopathy. We aimed to study the clinical and molecular features of a male child with a CACNA1S variant and depict the molecular sub-regional characteristics of different phenotypes associated with CACNA1S variants.
We presented a case of HypoPP with recurrent muscle weakness and hypokalemia. Genetic analyses of the family members revealed that the proband had a novel c.497 C > A (p.Ala166Asp) variant of CACNA1S, which was inherited from his father. The diagnosis of HypoPP was established in the proband as he met the consensus diagnostic criteria. The patient and his parents were informed to avoid the classical triggers of HypoPP. The attacks of the patient are prevented by lifestyle changes and nutritional counseling. We also showed the molecular sub-regional location of the variants of CACNA1S which was associated with different phenotypes.
Our results identified a new variant of CACNA1S and expanded the spectrum of variants associated with HypoPP. Early genetic diagnosis can help avoid diagnostic delays, perform genetic counseling, provide proper treatment, and reduce morbidity and mortality.

Hypokalemic periodic paralysis (HPP) is a heterogeneous group of diseases characterized by intermittent episodes of delayed paralysis of skeletal muscle with episodes of hypokalemia, caused by variants in CACNA1S or SCN4A genes, or secondary to thyrotoxicosis, Sjogren syndrome, primary aldosteronism, etc. HPP may be the only presentation in Andersen-Tawil syndrome in which the majority of cases are caused by pathogenic variants in the KCNJ2 gene. We present a case of a 29-year-old male with hypokalemic periodic paralysis. The patient began to experience recurrent weakness of the extremities at the age of 26, which was effectively treated with potassium supplementation. He had recently developed dry mouth, palpitations, weight loss, and even dyspnea, with a serum potassium level as low as 1.59 mmol/L. The results of auxiliary examinations showed Graves\' disease, and genetic testing indicated a missense variant, NM_000334.4 (SCN4A):c.3404G>A (p.R1135H). He did not experience periodic paralysis during follow-up after lifestyle guidance and treatment of thyrotoxicosis with radioactive iodine. It is a rare case of SCN4A p.R1135H gene variant combined with hyperthyroidism resulting in HPP with respiratory muscle paralysis to raise awareness of the disease and avoid misdiagnosis and missed diagnosis.

This study aimed to examine changes in electrolytes and acid-base status in primary and secondary hypokalaemic periodic paralysis (HypoPP), which will help early differential diagnosis of HypoPP. A total of 64 HypoPP patients were enrolled and relevant data from clinical records was collected. Overall, 64 patients (mean age 28.2±7.3 years) of which 58(91%) were males, with 39, 11 and 14 patients, respectively, diagnosed as primary HypoPP, thyrotoxic HypoPP, and other secondary HypoPPs at discharge, were assessed. Those with HypoPP secondary to conditions other than hyperthyroidism were more likely to develop acid-base imbalance (p<0.001); they had higher pH (p=0.046) and HCO3 levels (p=0.014) at baseline, and needed a higher dose of potassium supplement before the serum potassium level returned to normal (p=0.007) and a longer time to regain full muscle strength (p=0.004), compared with those with primary or thyrotoxic HypoPP. Emergent arterial blood gas analysis may aid early differential diagnosis of patients with primary and secondary HypoPP.

Unilateral paralysis is an alarming symptom with broad differential diagnoses, including stroke, Todd\'s paralysis, myelopathy, and peripheral neuropathy. Hypokalemic paralysis (HP), a neuromuscular disorder associated with muscle dysfunction, is caused by hypokalemia and manifests as symmetric proximal extremity muscle weakness. Unilateral paralysis has rarely been reported in the literature. Once hypokalemia is corrected, HP is usually reversible. Delayed diagnosis and treatment may result in fatal consequences. Here, we report an atypical case of unilateral weakness along with a review of the literature on unilateral HP.

垂体促甲状腺激素（TSH）细胞腺瘤是临床罕见的垂体腺瘤类型。本文报道1例合并周期性麻痹及雄激素异常升高的患者，以反复四肢麻痛、活动障碍起病，进而发现血钾低、睾酮水平显著升高，甲状腺激素明显升高而TSH水平未被抑制，垂体磁共振成像（MRI）提示垂体腺瘤，诊断为垂体TSH细胞腺瘤。完善术前准备后行手术治疗，术后甲状腺功能恢复正常，垂体MRI未见肿瘤残留及复发。.

To explore the clinical and genetic characteristics of five families with primary periodic paralysis (PPP). We reviewed clinical manifestations, laboratory results, electrocardiogram, electromyography, muscle biopsy, and genetic analysis from five families with PPP. Five families with PPP included: hypokalemic periodic paralysis type 1 (HypoPP1, CACNA1S, 1/5), hypokalemic periodic paralysis type 2 (HypoPP2, SCN4A, 2/5), normokalemic periodic paralysis (NormoPP, SCN4A, 1/5), and Andersen-Tawil syndrome (ATS, KCNJ2, 1/5). The basic clinical manifestations of five families were consistent with PPP, presenting with paroxysmal muscle weakness, with or without abnormal serum potassium. ATS was accompanied by ventricular arrhythmias, and skeletal and craniofacial anomalies, developing with a permanent fixed myopathy later. The electromyography showed diffuse myopathic discharge, and muscle biopsy showed tubular aggregates. Genetic testing revealed five families with PPP carried CACNA1S (R1242S), SCN4A (R675Q, T704M), and KCNJ2 (R218Q) respectively. The novel heterozygous R1242S mutation in CACNA1S caused a conformational change in the protein structure, and the amino acid of this mutation site was highly conserved among different species. SCN4A mutations led to two phenotypes of HypoPP2 and NormoPP. PPPs are autosomal dominant disorders of ion channel dysfunction characterized by episodic flaccid muscle weakness secondary to abnormal sarcolemmal excitability. PPPs are caused by mutations in skeletal muscle calcium channel CaV1.1 gene (CACNA1S), sodium channel NaV1.4 gene (SCN4A), and potassium channels Kir2.1, Kir3.4 genes (KCNJ2, KCNJ5), including HypoPP1, HypoPP2, NormoPP, HyperPP, and ATS, which have significant clinical and genetic heterogeneity. Diagnosis is based on the characteristic clinical presentation then confirmed by genetic testing.

Objective: To report a Chinese family with hypokalemic periodic paralysis (HOKPP) and investigate the clinical and pathogenic gene characteristics of the family. Methods: The clinical, electrophysiological and pathological data of the proband of the family were analyzed, and the information of the family was investigated in detail. The peripheral venous blood of the six members of the family was collected and their genomic DNA was extracted. The genes related to periodic paralysis analysis of the proband were performed by the second generation sequencing. The pathogenicity of the mutant protein was respectively analyzed by the bioinformatics software SIFT, Polyphen2 and Mutation Tasker. The cosegregation analysis of phenotype and genotype of the family was performed by the first generation sequencing. Results: There were 3 patients in the family with the onset age of 21 to 42 years old. All the patients manifested with vomiting as the first symptoms, then presented with muscle weakness accompanied by muscle soreness. The muscle weakness gradually relieved in 3 to 5 days. Creatine kinase (CK) of the proband significantly increased. Electromyographic exercise test was positive, however, electromyography and muscle pathological analysis were normal. The genes related to periodic paralysis analysis of the proband found a novel mutation (c.2458A>T (p.N.820Y)) of SCN4A gene which was located in the conservative region. The function analysis showed it was a pathogenic mutation. Moreover, the first generation sequencing confirmed that the mutation was cosegregated with patients in the family. Meanwhile, it was found that the proband\'s son carried the same mutation, but without any symptom, indicating that he was a pre-symptomatic patient. Conclusions: Vomiting can be one of the symptoms of the patients with HOKPP. The novel mutation of SCN4A gene c.2458 A>T is the pathogenic mutation of the family. Patients with periodic paralysis should be tested for blood potassium and genes as early as possible to facilitate early diagnosis and genetic counseling.
目的： 报道一个中国人低钾性周期性瘫痪（HOKPP）家系，探讨该家系的临床及致病基因特点。 方法： 对该家系先证者的临床、电生理及病理资料进行分析，并对该家系进行详细的调查；采集该家系6名成员的外周静脉血并抽提其基因组DNA，采用二代测序技术对先证者进行周期性瘫痪相关基因检测，对所发现突变采用SIFT、PolyPhen 2及Mutation Taster软件进行突变蛋白功能的致病性分析；采用一代测序技术进行家系的表型和基因型共分离研究。 结果： 该家系3代患者3例，发病年龄21~42岁，主要表现为发作性四肢无力，以呕吐为首发症状，伴肌肉酸痛，持续3~5 d后缓解；先证者发作时肌酶明显升高，缓解后长时程运动诱发试验阳性，肌电图及肌肉病理未见异常；先证者周期性瘫痪相关基因二代测序发现SCN4A基因c.2458A>T（p.N820Y）新突变，该突变位于SCN4A蛋白保守区域，功能预测为致病性突变，一代测序验证该突变与家系内患者共分离，同时发现先证者儿子携带相同突变，目前尚未发病，为症状前患者。 结论： HOKPP患者可以呕吐为临床表现；SCN4A基因新突变c.2458A>T为该家系的致病突变；对伴有呕吐的周期性瘫痪患者尽早行血钾和基因检测，有助于早期诊治和遗传咨询。.

OBJECTIVE: To explore the genetic basis for a child suspected for hypokalemic periodic paralysis.
METHODS: Clinical data of the patient was collected, and venous blood samples were taken from the patient and his parents for the extraction of genomic DNA. Next generation sequencing (NGS) with target capture was carried out to detect potential variants. Suspected variants were validated by Sanger sequencing.
RESULTS: The child developed fatigue without obvious reason at the age of 15. Laboratory test revealed hypokalemia but normal serum magnesium. Genetic testing discovered that he has carried two variants in the SLC12A3 gene, namely c.179C>T and c.539C>A. The patient was diagnosed with Gitelman syndrome.
CONCLUSIONS: For children with hypokalemia, genetic testing should be considered for the differential diagnosis of Gitelman syndrome from hypokalemia due to other causes.