Prevalence
According to three OMIM pages for this condition, about 78 families across the world are known to have this condition, this includes both familial and sporadic cases with confirmed genetic basis (thus, potential to spread to offspring and turn it into a familial case). Most (if not all) of these families are of East Asian (Japanese and Chinese in particular) descent. OMIM divided this condition into subtypes due to the different genetic causes and slightly different symptoms the three of them exhibit. The following list comprises the number of families described in medical literature each of these subtypes has:

# 164310OCULOPHARYNGODISTAL MYOPATHY 1; OPDM1: 37 families
# 618940OCULOPHARYNGODISTAL MYOPATHY 2; OPDM2: 30 families
# 619473OCULOPHARYNGODISTAL MYOPATHY 3; OPDM3: 11 families. History
This condition was first discovered in 1977 by E Sayotoshi et al. when they described an unspecified amount of people from 4 families who suffered from an "autosomal dominant, heredofamilial myopathy" which consisted in "slowly progressive ptosis and extraocular palsy, and weakness of the masseter, facial, and bulbar muscles, as well as distal involvement of the limbs starting around 40 years of age or later. "In 2019, Hiroyuki Ishiura et al. discovered a heterozygous trinucleotide repeat expansion in the 5-prime untranslated region of the LRP12 gene in 5 patients with the condition, the trinucleotide sequence consisted of one C (cytosine) and two Gs (guanine).
Beta-blockers may slow the heart rate to a dangerous level if prescribed with calcium channel blocker-type medications. Bradycardia is also part of the mammalian diving reflex. Diagnosis
A diagnosis of bradycardia in adults is based on a heart rate less than 60 BPM, although some studies use a heart rate of less than 50 BPM. This is determined usually either by palpation or ECG. If symptoms occur, a determination of electrolytes may be helpful in determining the underlying cause. Management
The treatment of bradycardia is dependent on whether or not the person is stable or unstable. Stable
Emergency treatment is not needed if the person is asymptomatic or minimally symptomatic. Unstable
If a person is unstable, the initial recommended treatment is intravenous atropine. Doses less than 0.5 mg should not be used, as this may further decrease the rate. If this is not effective, intravenous inotrope infusion (dopamine, epinephrine) or transcutaneous pacing should be used. Transvenous pacing may be required if the cause of the bradycardia is not rapidly reversible.In children, giving oxygen, supporting their breathing, and chest compressions are recommended. Epidemiology
In clinical practice, elderly people over age 65 and young athletes of both sexes may have sinus bradycardia. The US Centers for Disease Control and Prevention reported in 2011 that 15.2% of adult males and 6.9% of adult females had clinically-defined bradycardia (a resting pulse rate below 60 BPM). Society and culture
Records
Daniel Green holds the world record for the slowest heartbeat in a healthy human, with a heart rate measured in 2014 of 26 BPM.