Suppose you have noticed a pattern in your family in which you and other members have difficulty falling asleep or shorter sleep duration. In that case, you may wonder whether it is a hereditary condition.
Many health experts have said that certain lifestyle and bedtime habits, medications, and mental health issues contribute to insomnia.
However, emerging research suggests that insomnia could be genetic. Furthermore, scientists have found that certain rare insomnia diseases are linked to genetic mutations.
In this article, we will explore this research on insomnia and genetics, how to help prevent this condition, and more important details.
Is Insomnia Hereditary?
Scientists had previously found that sleep issues like insomnia were partially hereditary but only recently searched for the specific genetic cause. For the 2018 study, researchers analyzed the DNA of over 33,000 soldiers from European, African, and Latino Descent. They discovered a significant genetic link between insomnia and diabetes, and among the soldiers of European descent, a genetic tie between insomnia and depression.
Dr. Murray B. Stein led the study and describes how these connections suggest a particular shared genetic predisposition. “The genetic correlation between insomnia disorder and other psychiatric disorders, such as major depression, and physical disorders such as type 2 diabetes suggests a shared genetic diathesis for these commonly co-occurring phenotypes.”
Going more specifically into the DNA data, the research team found a link between insomnia and variants on chromosome 7. The soldiers of European descent also exhibited variants on chromosome 9. Furthermore, a chromosome 7 variant was similar to the AUTS2 gene, which is linked to alcohol consumption.
Stein adds that the variants are in areas already connected to sleep and circadian rhythms, which are part of the natural internal clock that controls the sleep-wake cycle. “Several of these variants rest comfortably among locations and pathways already known to be related to sleep and circadian rhythms. Such insomnia-associated loci may contribute to the genetic risk underlying a range of health conditions including psychiatric disorders and metabolic disease.”
Fatal Familial Insomnia
Fatal Familial Insomnia is an inherited neurological disorder that causes a person to exhibit increased insomnia symptoms and eventually lose the ability to stay asleep. Additional symptoms of fatal insomnia include concentration problems, short-term memory loss, extensive weight loss, poor coordination, high blood pressure, inconsistent body temperature, and excessive sweating and tearing. Though it is a rare disease, Fatal Familial Insomnia is deadly for those who acquire it.
A mutation in the PRNP gene is what causes Fatal Familial Insomnia. The PRNP gene provides the coding information for the production of the prion protein in the brain, and when this gene is mutated, it can lead to abnormal prion proteins. A buildup of these malformed prions can cause a breakdown of nerve cells, which is the basis for the disease.
The impact on the neurons causes a chain reaction that impairs the autonomic nervous system, the part of the body responsible for involuntary functions such as breathing, heart rate, and sweating. Furthermore, the decline in neurons is centered in the thalamus brain region – the area responsible for maintaining the body’s natural sleep-wake cycle. Therefore, the loss of nerve cells in the thalamus can result in insomnia symptoms.
Sporadic Fatal Insomnia
Like Fatal Familial Insomnia, Sporadic Fatal Insomnia is a prion disease due to a genetic mutation. However, Sporadic is not passed down through family members. Instead, this version of Fatal Insomnia is caused by a spontaneous mutation of prion proteins rather than abnormalities in the PRNP gene.
Are Other Sleep Disorders Genetic?
Insomnia is not the only sleep disorder with heredity links; researchers say genetics play a part in other sleep disorders. In some cases, the disorder may result from a combination of environmental components and shared genetic factors.
Hypersomnia is essentially the opposite of insomnia; instead of not being able to fall asleep, the individual tends to oversleep. Idiopathic is a term used to describe a condition or disease in which the cause is unknown.
People with idiopathic hypersomnia experience excessive daytime sleepiness (EDS) and are usually symptomatic for at least a month before diagnosis. Researchers estimate that idiopathic hypersomnia is linked to an autosomal dominant pattern in the individual’s genetic makeup.
Autosomal dominant means that a mutated non-sex gene from only one parent is enough to pass on a particular disease or condition to the child. Furthermore, men and women are equally likely to inherit or pass on these mutations.
Narcolepsy is a chronic disease linked to extreme tiredness during the day. Other major symptoms of narcolepsy include cataplexy, sleep paralysis, and hallucinations.
Cataplexy is when the individual experiences a sudden loss of muscle tone while awake. On the other hand, sleep paralysis is when an individual suddenly wakes up from sleep or is falling asleep only to discover they cannot move or speak. Experts say hallucinations may accompany sleep paralysis, and they usually happen as the person is dozing off or waking up.
According to researchers, if a close relative has narcolepsy, you have a higher chance of developing this condition compared to the rest of the population. However, that probability is still only between one and two percent.
More specifically, findings suggest that narcolepsy is closely associated with the Human Leukocyte Antigen (HLA) DR2/DQW1. The HLA system is linked to a person’s immune system and is regulated by genes from chromosome 6.
Restless Legs Syndrome (RLS)
RLS causes a person to develop an uncontrollable urge to move their legs, and this condition typically worsens at night, especially while resting. RLS frequently disrupts sleep for those who have it. According to reports, an estimated five to ten percent of adults and two to four percent of children in the U.S. have this condition, making it one of the more common sleep-related disorders.
Experts say people are three to six times more at risk for RLS if a close relative has it and believe the disorder likely follows an autosomal dominant genetic pattern.
Read More: Restless Leg Syndrome Guide
Circadian Rhythm Disorders
Circadian rhythms are part of the human body’s 24-hour internal clock, and one of their primary influences is sleep regulation. As such, a circadian rhythm disorder could impair an individual’s sleeping habits.
There are six known circadian rhythm disorders: delayed sleep phase syndrome (DSPS), advanced sleep phase type (ASPS), irregular sleep-wake type (ISWT), free-running type, jet lag type, and shift work type. While disorders like jet lag and shift work usually result from lifestyle factors, delayed sleep phase syndrome (DSPS) and advanced sleep phase type (ASPS) are linked to genetics.
Want to know more? Visit our full guide to the circadian rhythm disorders.
ASPS is when the individual goes to bed and wakes up abnormally early. In 2001, researchers discovered that ASPS was specifically linked to a mutation of the clock component hPER2.
DSPS is the most common circadian rhythm disorder and refers to when a person is prone to a later bedtime and wake-up time. To decipher the specific genetic correlation to DSPS, researchers studied the entire hClock gene, hPer3.
They looked at four haplotypes in this gene, which are sets of DNA variations usually inherited together. They found that the fourth haplotype, H4, was associated with an increased risk of DSPS.
Parasomnias are described as unusual nighttime behaviors such as talking in your sleep, sleepwalking, sleep paralysis, and night terrors. Sleepwalking – also known as Somnambulism – may be connected to your genetics.
Sleepwalking typically occurs during the deep non-REM sleep stage. Experts say children who have either one or both parents who have sleepwalked have a 45-percent chance of developing this parasomnia, a 23-percent increased risk compared to children whose parents don’t sleepwalk. More specifically, sleepwalking is linked to the HLA O501 and DQ-B1 genes.
Sleep apnea is one of the more prevalent sleep disorders, and it occurs when an individual has periodic breathing pauses while they are sleeping, leading to disrupted rest. Symptoms of sleep apnea include insomnia and excessive daytime sleepiness.
The two main forms of this disorder are Obstructive and Central. However, a third form of this disorder, Complex Sleep Apnea, occurs when individuals exhibit symptoms of Obstructive and Central Sleep Apnea.
Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is when gaps in breathing are because of a physical obstruction in the upper airway. Specifically, the throat muscles controlling areas like the tongue and soft palate will relax while you’re asleep. When this happens, the airway will narrow or completely close, which can temporarily cause your breathing to stop.
Researchers have discovered a certain genetic attribute that could be a risk factor for OSA. Several studies conducted in Japan and the United States found a correlation between the HLA-DR2 and obstructive sleep apnea. In the U.S. study specifically, the research team learned that individuals with obstructive sleep apnea had a higher frequency of the HLA-DR2 sequence.
Central Sleep Apnea
Central sleep apnea, like obstructive, generates frequent breathing pauses while a person sleeps. However, the difference between these two forms of sleep apnea is what causes this.
Central sleep apnea happens when the brain does not send the right signals to your breathing muscles. As a result, your breathing can periodically start and stop during the night. Experts say a specific type of CSA, congenital central hypoventilation syndrome (CCHS), may be genetic.
Get More Info: Central Sleep Insomnia – Diagnosis and Treatment Options
Frequently Asked Questions
Can insomnia go away?
Acute or short-term insomnia is usually caused by temporary stress and disappears on its own. However, frequent insomnia symptoms may require lifestyle changes such as better sleeping habits, avoiding caffeine and alcohol, and finding ways to reduce stress.
However, if your insomnia fails to improve, you will need to see a doctor who can help evaluate and diagnose your condition. For example, you may find that your insomnia is due to a separate issue such as circadian rhythm disorder or obstructive sleep apnea.
By properly diagnosing the root cause of your insomnia, you are better equipped to treat it. While some healthcare professionals may prescribe medications for insomnia, cognitive behavioral therapy (CBT) has emerged as a popular treatment option.
Insomnia due to rare prion diseases, unfortunately, does not yet have a known cure. For those living with fatal insomnia, treatment is focused on making the individual as comfortable as possible during their final months.
Need help? See our complete guide to the insomnia – causes, diagnosis and prevention.
Can you prevent insomnia?
Although Familial and Sporadic Insomnia are deadly neurological disorders, scientists hope emerging research may provide a solution. Clinical trials are currently underway to determine if the drug doxycycline may prevent the emergence of Fatal Familial Insomnia in people who have a family history of the disease and, therefore, are most at risk. Doxycycline normally treats bacterial infections, but the researchers hope the drug may reduce abnormal prion proteins in the brain that cause the degenerative disease.
Regarding common self-reported insomnia symptoms, you should reduce your risk by regularly practicing good sleep hygiene. Some examples of good habits for quality rest are keeping a consistent bedtime and wake-up time, avoiding electronics before bed, and establishing a nightly routine to wind down and relax.
We also mentioned earlier that some insomnia cases are symptomatic of other disorders such as obstructive sleep apnea. One of the biggest risk factors for this form of sleep apnea is carrying excess weight. Therefore, regular exercise and maintaining a healthy weight could prevent obstructive sleep apnea and insomnia.
Sources and References:
-  Murray B. Stein, Michael J. McCarthy, Chia-Yen Chen, Sonia Jain, Joel Gelernter, Feng He, Steven G. Heeringa, Ronald C. Kessler, Matthew K. Nock, Stephan Ripke, Xiaoying Sun, Gary H. Wynn, Jordan W. Smoller, Robert J. Ursano, “Genome-wide analysis of insomnia disorder”, Molecular Psychiatry, 2018
-  “Can't sleep? Could be down to genetics”, Science Daily, March 9, 2018
-  “Fatal familial insomnia“, National Center for Advancing Translational Sciences, November 11, 2020
-  Jennifer L. Blase MPH, Laura Cracco PhD, Lawrence B. Schonberger MD, Ryan A. Maddox PhD, Yvonne Cohen BS, Ignazio Cali MS, Ermias D. Belay MD, “Sporadic Fatal Insomnia in an Adolescent”, National Library of Medicine
-  Reza Bidaki MD, Mina Zarei MD, Ali Khorram Toosi MD, Mitra Hakim Shooshtari MD, “A Review on Genetics of Sleep Disorders“, National Library of Medicine
-  “Autosomal dominant inheritance”, National Cancer Institute
-  “Narcolepsy Fact Sheet”, National Institute of Neurological Disorders and Stroke, September 30, 2020
-  “Human Leukocyte Antigen (HLA) System”, Merck Manual, April 2020
-  “Restless legs syndrome”, Medline Plus
-  Liu Wenjing, “Mini-review: Genetics of Common Types of Sleep Disorders”, AIP Publishing
-  Danny J. Eckert PhD, Amy S. Jordan PhD, Pankaj Merchia MD, Malhotra MD, FCCP, Atul. “Central Sleep Apnea Pathophysiology and Treatment”, National Library of Medicine
-  “Know the difference: Is it insomnia or just a few nights of bad sleep?”, Geisinger Medical Group, January 4, 2018
-  Gianluigi Forloni, Mauro Tettamanti, Ugo Lucca, Yasmin Albanese, Elena Quaglio, Roberto Chiesa, Alessandra Erbetta, Flavio Villani, Veronica Redaelli, Fabrizio Tagliavini, Vladimiro Artuso, Ignazio Router, “Preventive study in subjects at risk of fatal familial insomnia: Innovative approach to rare diseases”, National Library of Medicine