Here I present: “Long QT-syndrome with Sinus Bradycardia“, Victor McKusick, Mendelian Inheritance in Man’, 1966. 長QT綜合徵伴有竇性心動過緩。(LQTS).
INTRODUCTION.
Congenital long QT syndrome (LQTS) is electrocardiographically characterized by a prolonged QT interval and polymorphic ventricular arrhythmias. These cardiac arrhythmias may result in recurrent syncope, seizure, or sudden death.
Long QT syndrome type-4 can be caused by mutation in the ANK2 gene. Loss-of-function mutations in ANK2 can result in a broad spectrum of clinical cardiac phenotypes. Carriers of some mutations display QT interval prolongation, stress- and/or exercise-induced polymorphic ventricular arrhythmia, syncope, and sudden cardiac death. Patients with other variants show clinical phenotypes, sometimes mild, extending beyond LQTS, leading to the label ‘ankyrin-B syndrome.’ These phenotypes include bradycardia, sinus arrhythmia, delayed conduction/conduction block, idiopathic ventricular fibrillation, and catecholaminergic polymorphic ventricular tachycardia.
There is evidence long QT syndrome type-4 can also be caused by mutation in the ANK2 gene on cytogenetic location 4q25-q26 and genomic coordinates 4:112,705,622-113,383,736. The screenshot of the ANK2 gene 678,115 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides ANK2 in the 4q25-q26 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 4:112,648,004 | MIR302D | Micro RNA 302D |
| 4:112,648,183 | MIR302A | Micro RNA 302A |
| 4:112,648,363 | MIR302C | Micro RNA 302C |
| 4:112,648,485 | MIR302B | Micro RNA 302B |
| 4:112,705,622 | ANK2 | Ankyrin-2, nonerythrocytic |
| 4:113,200,001 | SYISL | SYNPO2 intron sense long noncoding RNA |
| 4:113,451,032 | CAMK2D | Calcium/calmodulin protein kinase II-delta |
| 4:113,900,284 | ARSJ | Arylsulfatase J |
| 4:114,598,402 | UGT8 | UDP glycosyltransferase 8 |
| 4:114,827,763 | NDST4 | N-deacetylase/N-sulfotransferase 4 |
