Familial hypokalemic periodic paralysis (HOPP) is a rare autosomal-dominant disease characterized by reversible attacks of muscle weakness occurring with episodic hypokalemia. Mutations in the skeletal muscle calcium (CACNA1S) and sodium channel (SCN4A) genes have been reported to be responsible for familial HOPP. Fifty-one HOPP patients from 20 Korean families were studied to determine the relative frequency of the known mutations and to specify the clinical features associated with the identified mutations. DNA analysis identified known mutations in 12 families: 9 (75%) were linked to the CACNA1S gene and 3 (25%) to the SCN4A gene. The Arg528His mutation in the CACNA1S gene was found to be predominant in these 12 families. Additionally, we have detected one novel silent exonic mutation (1950C>T) in the SCN4A gene. As for a SCN4A Arg669His mutation, incomplete penetrance in a woman was observed. Characteristic clinical features were observed both in patients with and without mutations. This study presents comprehensive data on the genotype and phenotype of Korean families with HOPP.
Adolescent ; Adult ; Calcium Channels/*genetics ; Child ; Child, Preschool ; Genotype ; Humans ; Hypokalemic Periodic Paralysis/*genetics ; Infant ; *Mutation ; Phenotype ; Sodium Channels/*genetics

Despite a few genes that do not encode ion channels have been identified as implicating some kinds of human idiopathic epilepsies(IE) in recent years, but genetic discoveries have shown the ion channels to play a central role in genetic pathomechanism of IE. The gene mutations of ion channels are a common cause of some rare monogenic IE which could be so-called as channelopathies, and able to be applied to account for the questioned epileptic syndrome to minority of families and sporadic cases. However, more frustrating has been from the genetic research on more common IE with complex inheritance due to the unknown mode of inheritance, the phenotypic heterogeneity and the uncertainty of genetic overlap among syndrome subtypes, which have limited gene mapping. Absence epilepsy is a kind of common IE subtype and shows a complex way to inherit. Evidences from heredity investigation indicate that eleven genes are correlated with absence epilepsy, of which four encode the neuronal calcium channel subunits. Therefore, calcium channel genes may be considered as important candidates for involving in absence epilepsy. To focus the genetics research on calcium channel genes of absence epilepsy may be opening an optimal gate to the pathogenetic study of more common IE with complex inheritance, and benefit to elucidate the molecular mechanisms of absence epilepsy finally, one of the more common IE subtypes with complex inheritance.
Calcium ; metabolism ; Calcium Channels ; genetics ; physiology ; Epilepsy, Absence ; genetics ; physiopathology ; Genetic Predisposition to Disease ; genetics ; Humans ; Models, Biological

Recently, more and more studies have discovered that some diseases result from gene defect and functional variation of ion channels, which are called ion passage diseases or ion channelopathies. Meanwhile, it has been found that even though many diseases do not fall into the category of the ion passage disease, some links or passages during the disease development are closely related with the malfunction of ion channels, and many drugs can prevent and cure these diseases by acting on ion channels. Therefore, the relationship between physiology/pathophysiology and ion channels is gradually becoming one of the hot topics in the current researches. The recent progress in the researches on the relationship between penile erection and ion channels is briefly reviewed in this article.
Calcium Channels ; physiology ; Chloride Channels ; physiology ; Connexin 43 ; genetics ; Erectile Dysfunction ; etiology ; Humans ; Ion Channels ; physiology ; Male ; Penile Erection ; physiology ; Potassium Channels ; physiology

OBJECTIVE: To analyze the clinical phenotype and genetic characterization of a child with early infantile epileptic encephalopathy. METHODS: The proband was subjected to history taking and was diagnosed based on his clinical manifestation, magnetic resonance imaging (MRI) and whole exome sequencing (WES). Sanger sequencing was carried out to determine the origin of pathogenic variant. RESULTS: The proband unconsciously tilts his head to one side with squint, which revealed an abnormal discharge. MRI indicated suspicious abnormal signal shadow in the left posterior frontal cortex in addition with inflammation signs in the right maxillary sinus and ethmoid sinus. WES revealed that the proband has carried a heterozygous c.5789G>A variant in the CACNAIA gene. The result of Sanger sequencing was in keeping with that of WES. Neither of his parents has carried the same variant. CONCLUSION The heterozygous c.5789G>A variant of the CACNAIA gene probably underlay the early infantile epileptic encephalopathy 42 in the proband, which has a de novo origin.
Calcium Channels/genetics* ; Genetic Testing ; Heterozygote ; Humans ; Infant ; Mutation ; Spasms, Infantile/genetics* ; Whole Exome Sequencing

OBJECTIVETo construct a rat model of chronic nonbacterial prostatitis (CP) and investigate the difference in the quantitative expression of voltage-dependent calcium channels of prostate smooth muscle cells (PSMCs) between the models and controls.

METHODSWe established a CP rat model by estrogen induction, cultured and purified the PSMCs in vitro, and extracted total RNA by Trizol. Then we measured the mRNA expression of the cal subunit in the calcium channel subtypes by reverse transcription and SYBR Green I real time RT-PCR, and compared it with that of the controls.

RESULTSThe expressions of the L-, T- and P/Q-type calcium channels were found in both the CP and control groups, and that of the CaV1.2 L-type calcium channel was significantly increased in the former as compared with the latter (0.048 +/- 0.024 versus 0.031 +/- 0.015, t = 2.846, P = 0.007), but there were no statistically significant differences in the T- and P/Q-type calcium channels between the two groups.

CONCLUSIONThe number of CaV1.2 L-type calcium channels of PSMCs and calcium influx were increased in CP patients, which may be involved in the mechanism of CP.

Animals ; Calcium Channels, L-Type ; metabolism ; Calcium Channels, Q-Type ; metabolism ; Calcium Channels, T-Type ; metabolism ; Estradiol ; pharmacology ; Male ; Myocytes, Smooth Muscle ; metabolism ; Prostate ; metabolism ; Prostatitis ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar

The acrosome reaction is a Ca(2+)-dependent exocytotic process that is a prerequisite step for fertilization. External calcium entry through voltage-activated Ca(2+)channels is known to be essential in inducing the acrosome reaction of mammalian spermatozoa. Due to their complex geometry, however, electrophysiological identification of sperm Ca(2+)channels has been limited. Here we identified Ca(2+)channel mRNAs expressed in motile human sperm using RT-PCR and their levels were compared using RNase protection assays. L-type, non- L-type, and T-type Ca(2+)channel mRNAs were detected by RT-PCR using degenerate primers. Cloning and sequencing of the PCR products revealed alpha1B, alpha1C, alpha1E, alpha1G, and alpha1H sequences. RT-PCR using specific primers repeatedly detected alpha1B, alpha1C, alpha1E, alpha1G, and alpha1H mRNAs, and additionally alpha1I mRNA. But alpha1A and alpha1D messages were not detected. Relative expression levels of the detected Ca(2+)channel subtypes were compared by RNase protection assays. The abundance of detected mRNA messages was in the following order: alpha1H> or =alpha1G> or =alpha1E> or =alpha1B>alpha1C>alpha1I. These findings indicated that human motile sperm express multiple voltage-activated Ca(2+)channel RNAs among which T-type and non-L-type channel messages are likely to be predominantly expressed. Based on their relative expression levels, we propose that not only T-type but also non-L-type calcium channels may be major gates for the external calcium influx, required for the acrosome reaction.
Calcium/*metabolism ; Calcium Channels/biosynthesis/classification/*genetics ; Human ; Male ; RNA, Messenger/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa/*metabolism

The primary cilium of renal epithelia acts as a transducer of extracellular stimuli. Polycystin (PC)1 is the protein encoded by the PKD1 gene that is responsible for the most common and severe form of autosomal dominant polycystic kidney disease (ADPKD). PC1 forms a complex with PC2 via their respective carboxy-terminal tails. Both proteins are expressed in the primary cilia. Mutations in either gene affect the normal architecture of renal tubules, giving rise to ADPKD. PC1 has been proposed as a receptor that modulates calcium signals via the PC2 channel protein. The effect of PC1 dosage has been described as the rate-limiting modulator of cystic disease. Reduced levels of PC1 or disruption of the balance in PC1/PC2 level can lead to the clinical features of ADPKD, without complete inactivation. Recent data show that ADPKD resulting from inactivation of polycystins can be markedly slowed if structurally intact cilia are also disrupted at the same time. Despite the fact that no single model or mechanism from these has been able to describe exclusively the pathogenesis of cystic kidney disease, these findings suggest the existence of a novel cilia-dependent, cyst-promoting pathway that is normally repressed by polycystin function. The results enable us to rethink our current understanding of genetics and cilia signaling pathways of ADPKD.
Calcium ; Cilia* ; Genetics ; Kidney Diseases, Cystic ; Polycystic Kidney, Autosomal Dominant* ; Transducers ; TRPP Cation Channels*

Episodic ataxia (EA) is a group of disorders characterized by recurrent spells of vertigo, truncal ataxia, and dysarthria. Episodic ataxia type 2 (EA2), the most common subtype of EA, is an autosomal dominant disease caused by mutation of the CACNA1A gene. EA2 has been rarely reported in the Chinese population. Here we present an EA2 family admitted to Xiangya Hospital in October 2018. The proband was a 22-year-old male who complained of recurrent spells of vertigo, slurred speech, and incoordination for 4 years. Brain magnetic resonance imaging (MRI) showed cerebellar atrophy. He had neuropsychological development disorder in childhood, and cognitive assessment in adulthood showed cognitive impairment. The proband's mother and grandmother had a similar history. Peripheral blood samples from the proband and family members were collected, and genomic DNA was isolated. Whole exome sequencing of the proband detected a heterozygous frameshift mutation c.2042_2043del (p.Q681Rfs*100) of CACNA1A gene. This mutation was verified in the proband and 2 family members using Sanger sequencing. One family member carrying this mutation was free of symptoms and signs, suggesting an incomplete penetrance of the mutation. We reported a variant c.2042_2043del of CACNA1A gene as the pathogenic mutation in a Chinese EA2 family for the first time. This case enriched the clinical spectrum of CACNA1A related EA2, and contributed to the understanding of clinical and genetic characteristics of EA2 to reduce misdiagnosis.
Adult ; Ataxia ; Calcium Channels/genetics* ; Humans ; Male ; Mutation ; Nystagmus, Pathologic ; Pedigree ; Vertigo ; Young Adult

Action Potentials ; Animals ; Calcium Channels, L-Type ; genetics ; Dogs ; Heart Atria ; metabolism ; Kv Channel-Interacting Proteins ; genetics ; RNA, Messenger ; analysis ; Shal Potassium Channels ; genetics

A growing body of evidence, including studies using genetically engineered mouse models, has shown that Ca2+ cycling and Ca2+ -dependent signaling pathways play a pivotal role in cardiac hypertrophy and heart failure. In addition, recent studies identified that mutations of the genes encoding sarcoplasmic reticulum (SR) proteins cause human cardiomyopathies and lethal ventricular arrhythmias. The regulation of Ca2+ homeostasis via the SR proteins may have potential therapeutic value for heart diseases such as cardiomyopathy, heart failure and arrhythmias.
Animals ; Animals, Genetically Modified ; Arrhythmia/genetics ; Calcium/*metabolism ; Calcium Channels/genetics/*physiology ; Calcium-Binding Proteins/genetics/*physiology ; Cardiac Output, Low/genetics ; Cardiomyopathies/genetics ; Heart Diseases/*etiology/genetics/metabolism ; Humans ; Mutation/genetics ; Research Support, Non-U.S. Gov't ; Sarcoplasmic Reticulum/metabolism