Kearns-Sayre syndrome

Kearns-Sayre Syndrome (KSS) Overview

Kearns-Sayre syndrome (KSS) is a rare neuromuscular disorder that affects various parts of the body, including the eyes, heart, and muscles. It is caused by defects in the DNA of mitochondria, which are responsible for producing most of the body's energy.

Key Features:

• Rare occurrence: KSS affects about 1 in 100,000 people [11].
• Mitochondrial defect: The condition is caused by abnormalities in the DNA of mitochondria, leading to impaired energy production in cells.
• Progressive multisystem disorder: KSS involves progressive damage to multiple systems, including the eyes, heart, and muscles.
• Age of onset: Symptoms typically develop before age 20 [1], with some cases reported as early as infancy [12].

Common symptoms:

• Ptosis (droopy eyelids): A characteristic feature of KSS, often affecting one or both eyes [3].
• Progressive external ophthalmoplegia (PEO): Weakness and paralysis of the eye muscles.
• Pigmentary retinopathy: Abnormal pigmentation in the retina.
• Cerebellar ataxia: Difficulty with coordination and balance.
• Heart block: Abnormal heart rhythms.

Other features:

• Ragged red fibers: A hallmark feature of mitochondrial myopathies, including KSS [5].
• Deafness: Some individuals may experience hearing loss.
• Pancreatic problems: Pearson syndrome, a related condition, can lead to severe anemia and pancreatic issues [12].

References:

[1] Kearns-Sayre syndrome (KSS) is a rare neuromuscular condition that impacts your eyes and other parts of your body, including your heart. It happens due to a defect in the DNA of mitochondria, which help produce most of your body’s energy. Most people with KSS develop symptoms before age 20.

[2] Kearns-Sayre syndrome is a condition caused by defects in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use. This process is called oxidative phosphorylation.

[3] Kearns-Sayre syndrome (KSS) is a rare multisystemic disorder. An important clinical symptomatic feature is the presence of droopy eyelids (ptosis) in one or both eyes.

[5] Kearns–Sayre syndrome (KSS), oculocraniosomatic disorder or oculocranionsomatic neuromuscular disorder with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age.

[11] KSS is a rare neuromuscular disorder that is caused by abnormalities in mitochondria. Mitochondria are small structures in cells that produce the energy needed for your cells to function. KSS is rare. Researchers estimate that it affects about 1 in 100,000 people.

Note: The above information is based on the provided context and may not be an exhaustive list of symptoms or features associated with Kearns-Sayre syndrome.

Early Signs and Symptoms

Kearns-Sayre syndrome (KSS) typically affects individuals before the age of 20, with the first symptoms often appearing in the eyes. The early signs and symptoms include:

• Difficulty seeing, especially in dark environments, due to damage to the retina (pigmentary retinopathy) [1]
• Progressive paralysis of certain eye muscles, including the eyelid (ptosis), leading to chronic progressive external ophthalmoplegia [2]

Additional Symptoms

As KSS progresses, other symptoms may develop, including:

• Muscle weakness, particularly in the proximal muscles
• Central nervous system (CNS) involvement, such as problems with coordination and balance (ataxia)
• Developmental delays
• Short stature (dwarfism)
• Hearing loss or deafness [7]

Ocular Symptoms

KSS is characterized by a range of ocular symptoms, including:

• Progressive external ophthalmoplegia (PEO), which impairs eye movement and causes drooping eyelids (ptosis) [11]
• Pigmentary retinopathy, which can cause night blindness or diminished visual acuity [12]

Other Symptoms

Additional symptoms may include:

• Mild skeletal muscle weakness
• Heart block (a type of cardiac arrhythmia)
• Short stature
• Other signs and symptoms may be present as well [8][10]

It's essential to note that KSS is a rare genetic condition, and the exact prevalence is unknown. However, it has been estimated to occur in approximately 1-3 per 100,000 individuals [3].

Diagnostic Tests for Kearns-Sayre Syndrome

Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder that requires a comprehensive diagnostic approach to confirm the diagnosis. The following tests can aid in diagnosing KSS:

• Genetic testing: Genetic testing can confirm the presence of large-scale deletions in mtDNA, which is characteristic of KSS [5][9]. This test involves analyzing DNA samples from blood or tissue.
• Muscle biopsy: A muscle biopsy may reveal ragged red fibers, which are indicative of mitochondrial dysfunction [11].
• Electroretinography (ERG): ERG can further evaluate the eye and detect pigmentary retinitis, a hallmark feature of KSS [10][12].
• Spinal tap (lumbar puncture): A spinal tap may reveal elevated protein and lactate levels in the cerebrospinal fluid, which can aid in diagnosing KSS [11].
• Electrocardiogram (ECG): An ECG can evaluate heart function and detect any abnormalities associated with KSS [14].

Other diagnostic tests

In addition to these specific tests, a thorough medical history and physical examination are essential for identifying the characteristic triad of symptoms in KSS. Blood tests may reveal elevated serum lactate and creatinine kinase levels, which can aid in diagnosing KSS [8][9]. A comprehensive diagnostic approach involving multiple tests is necessary to confirm the diagnosis of Kearns-Sayre syndrome.

References:

[5] Molecular Diagnosis: Genetic testing for large-scale deletions in mtDNA [8] While CPEO is a clinical diagnosis, laboratory studies can aid in confirming the diagnosis, as well as ruling out alternate diagnoses. [9] The diagnosis of Kearns-Sayre Syndrome is primarily clinical, based on the characteristic triad of symptoms. A thorough medical history and physical examination are essential for identifying the syndrome's features. Genetic Testing. Genetic testing can confirm the presence of mtDNA deletions characteristic of KSS. Blood tests may reveal ... [10] Diagnostic tests might include: Genetic tests (taken from blood or tissue samples) Muscle biopsy; Electroretinography (ERG; to further evaluate the eye) Spinal tap (to assess the cerebrospinal ... [11] Sep 27, 2023 — Perform a lumbar puncture and measure protein and lactate levels in the CSF. · Muscle biopsy may reveal ragged red fibers (as is shown in the ... [12] Kearns-Sayre syndrome is a condition caused by defects in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use.This process is called oxidative phosphorylation.Although most DNA is packaged in chromosomes within the nucleus (nuclear DNA), mitochondria also have a small amount of their own DNA, called mitochondrial DNA (mtDNA). [14] Diagnosis. Diagnosis. Clinical evaluation. The provider will review your medical history and symptoms. Specialized tests. Tests for Kearns-Sayre syndrome may include an electrocardiogram of the heart, evaluation of lactic acid levels in the blood and spinal fluid, biopsy of the muscles to identify abnormalities in the muscle tissue (known as ...

Treatment Options for Kearns-Sayre Syndrome

Kearns-Sayre syndrome (KSS) is a rare genetic disorder that affects the mitochondria, leading to various symptoms such as ophthalmoparesis, pigmentary retinopathy, and cardiac conduction block. While there is no cure for KSS, several treatment options are available to manage its symptoms.

Coenzyme Q10 (CoQ10)

CoQ10 has been approved by the US Food and Drug Administration (FDA) for the treatment of mitochondrial disease, including Kearns-Sayre syndrome [12]. Studies have shown that CoQ10 supplementation can improve muscle strength and reduce fatigue in patients with KSS.

Folic Acid Supplementation

Supplementation of folic acid has been suggested to enhance cerebrospinal fluid protein levels in patients with KSS [7].

Hormone Replacement Therapy

Hormone replacement therapy may be necessary for patients with KSS who experience hormonal imbalances [2].

Cardiac Management

Regular follow-up with a cardiologist is recommended, especially for patients with high-grade heart block. In some cases, a permanent pacemaker or implantable cardioverter-defibrillator (ICD) may be necessary to manage cardiac conduction problems [8][9].

Other Treatments

Occupational and physical therapy can help improve strength, coordination, and overall quality of life in patients with KSS [7]. However, it is essential to note that treatment for KSS is generally symptomatic and supportive, as there is currently no effective way to treat the underlying mitochondrial abnormalities.

References:

[2] - Your care team may include: Eye care specialist (ophthalmologist). Hearing specialist (audiologist). Heart specialist (cardiologist). Hormone-related disease expert (endocrinologist). [7] - Hormone replacement; Supplementation of folic acid to enhance cerebrospinal fluid; Occupational and physical therapy to help with strength, coordination and ... [8] - Treatment of KSS is supportive. Regular follow-up with a cardiologist is recommended. In those with high-grade heart block, a permanent pacemaker/implantable ... [9] - Treatment. There is currently no effective way to treat mitochondria abnormalities in KSS. Treatment is generally symptomatic and supportive. Management of ... [12] - CoQ10 has been approved by the US Food and Drug Administration (FDA) for treatment of mitochondrial disease. ... Most cases of proven 5-MTHF CSF deficiency in mitochondrial disease have occurred in patients with Kearns-Sayre syndrome.

Differential Diagnosis of Kearns-Sayre Syndrome

Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder that can be challenging to diagnose due to its overlapping symptoms with other conditions. The differential diagnosis for KSS includes:

• Mitochondrial cytopathies: These disorders can have both genetic and phenotypic overlap with KSS, making them a key consideration in the differential diagnosis (8).
• Leigh syndrome: This is another mitochondrial disorder that can present with similar symptoms to KSS, including progressive external ophthalmoplegia (PEO) and pigmentary retinopathy (6).
• Chronic progressive external ophthalmoplegia (CPEO): CPEO is a mitochondrial disorder that can cause PEO, which is also a hallmark of KSS. The differential diagnosis between the two conditions may be necessary in some cases (6).
• Ataxia neuropathy spectrum: This condition can cause coordination and balance problems (ataxia) and nerve issues, which are similar to some symptoms seen in KSS (3).

Key Features for Differential Diagnosis

When considering a differential diagnosis for KSS, it's essential to look out for the following key features:

• Age of onset: KSS typically presents before age 20 years.
• PEO and pigmentary retinopathy: These are hallmark symptoms of KSS that can help differentiate it from other conditions.
• Muscle weakness and short stature: These symptoms may also be present in KSS, but they can be seen in other mitochondrial disorders as well.

References

(6) Aug 28, 2024 - Differential diagnosis · other mitochondrial disorders, e.g. Leigh syndrome · chronic progressive external ophthalmoplegia (CPEO): Kearns-Sayre ... (8) Aug 13, 2024 - The differential diagnosis includes mitochondrial cytopathies that can have both genetic and phenotypic overlap with Kearns-Sayre syndrome. (3) May 19, 2022 - They include, but aren't limited to: Ataxia neuropathy spectrum, which causes coordination and balance problems (ataxia) and nerve issues ...