| 16485 | P16388 | KCNA1_MOUSE | Potassium voltage-gated channel subfamily A member 1 (MBK1) (MKI) (Voltage-gated potassium channel subunit Kv1.1) | DISRUPTION PHENOTYPE | Mice are born at the expected Mendelian rate. After three weeks, mice begin to display episodic eye blinking, twitching of whiskers, forlimb padding, arrested motion and a hyperstartle response. About 50% of the homozygotes die between the third and the fifth week after birth. Surviving mice continue to display spontaneous seizures occurring once or twice every hour throughout adult life (PubMed:9581771). The fecundity of homozygotes is extremely low (PubMed:9581771). Mutant mice display interictal cardiac abnormalities, including a fivefold increase in atrioventricular conduction blocks, brachycardia and premature ventricular contractions; this may lead to sudden unexplained death in epilepsy (PubMed:20392939). Mutant mice have slightly elevated heart rates; they all have a reduced livespan and are subject to sudden death after presumed seizure activity and sinus bradycardia (PubMed:25377007). About 70% of the mutant mice have an enlarged hippocampus and ventral brain cortex (PubMed:17250763). Mutant mice show a temperature-sensitive alteration in neuromuscular transmission, causing nerve hyperexcitability when exposed to cold and delayed repetitive discharge after a single nerve stimulation (PubMed:9736643). After 2 minutes of swimming in cold water, mutant mice have impaired motor control; they fall over when placed on dry ground and exhibit severe neuromyotonia with violent tremors that decrease with time, leading to full recovery after twenty minutes (PubMed:9736643). Mutant mice have an increased frequency of spontaneous postsynaptic currents in Purkinje cells, impaired ability to maintain their balance on a thin stationary rod, but perform as well as wild-type on a rotarod (PubMed:10191303). Mutant mice have a normal hearing threshold, but altered brainstem responses to auditory stimuli and reduced sensitivity to small changes in sound location (PubMed:22396426). Mutant mice display no alteration of the islet of Langerhans, but have reduced blood glucose levels and increased insulin secretion in response to a glucose stimulus (PubMed:21483673). {ECO:0000269|PubMed:10191303, ECO:0000269|PubMed:17250763, ECO:0000269|PubMed:20392939, ECO:0000269|PubMed:21483673, ECO:0000269|PubMed:22396426, ECO:0000269|PubMed:25377007, ECO:0000269|PubMed:9581771, ECO:0000269|PubMed:9736643}. |