Laurence-Moon syndrome

Laurence-Moon syndrome, also known as Laurence-Moon-Biedl syndrome, is a rare genetic disorder that affects multiple systems in the body.

Key Features:

• Intellectual disability or mental retardation [2][4]
• Pigmentary retinopathy (a condition affecting the retina) [1][7]
• Hypogenitalism (underdeveloped genitalia) [3][11]
• Spastic paraplegia (progressive weakness and stiffness of the legs) [2][5]
• Childhood onset of ataxia (loss of coordination and balance) [5][11]

Other Possible Features:

• Polydactyly (extra fingers or toes) [8][9]
• Obesity [6][9]
• Retinal dystrophy (a condition affecting the retina) [3][12]
• Hypogonadism (underdeveloped gonads) [5][11]
• Renal abnormalities (kidney problems) [8][9]

Causes:

Laurence-Moon syndrome is caused by mutations in the PNPLA6 gene, which codes for the neuropathy target esterase (NTE) protein [3][15]. This mutation leads to a complex array of symptoms affecting multiple systems in the body.

References:

[1] Context 4 [2] Context 2 and 4 [3] Context 3 and 8 [5] Context 11 [6] Context 6 [7] Context 7 [8] Context 9 [9] Context 9 [11] Context 13 [15] Context 15

Laurence-Moon syndrome, also known as Laurence-Moon-Biedl syndrome (LMBBS), is a rare genetic disorder that affects many different parts of the body. The signs and symptoms of this condition can vary but may include:

• Cerebellar ataxia: A neurological sign characterized by difficulty with coordination and balance.
• Eye abnormalities: Primarily affecting the choroid and retina, which can lead to reduced visual function or blindness.
• Peripheral neuropathy: Damage to the peripheral nerves, which can cause pain, numbness, and weakness in the hands and feet.
• Spastic paraplegia: Progressive weakness and stiffness of the legs, which can lead to difficulty walking or standing.
• Intellectual disability: A range of cognitive impairments that can affect learning, memory, and problem-solving abilities.
• Congenital or childhood hypopituitarism: Underactive pituitary gland, which can lead to hormonal imbalances and growth problems.
• Short stature: Individuals with Laurence-Moon syndrome may experience growth delays or short stature.

These symptoms can manifest at different stages of life, from birth to adulthood. The severity and progression of the condition can vary significantly among individuals.

References:

• [1] Signs & Symptoms. The major signs that people present with which raise the suspicion that they may have LNMS are summarized below.
• [2] Laurence-Moon syndrome is a rare condition that affects many different parts of the body. Signs and symptoms vary but may include cerebellar ataxia; eye abnormalities (primarily affecting the choroid and retina); peripheral neuropathy; spastic paraplegia (progressive weakness and stiffness of the legs); intellectual disability; congenital (from birth) or childhood hypopituitarism; and short ...
• [11] Laurence-Moon syndrome is a rare condition that affects many different parts of the body. Signs and symptoms vary but may include cerebellar ataxia; eye abnormalities (primarily affecting the choroid and retina); peripheral neuropathy; spastic paraplegia (progressive weakness and stiffness of the legs); intellectual disability; congenital (from birth) or childhood hypopituitarism; and short ...
• [15] Laurence-Moon syndrome is a rare condition that affects many different parts of the body. Signs and symptoms vary but may include cerebellar ataxia; eye abnormalities (primarily affecting the choroid and retina); peripheral neuropathy; spastic paraplegia (progressive weakness and stiffness of the legs); intellectual disability; congenital (from birth) or childhood hypopituitarism; and short ...

Laurence-Moon syndrome, also known as Bardet-Biedl syndrome, is a rare genetic disorder that affects multiple systems in the body. Diagnostic tests for this condition are crucial to confirm the diagnosis and rule out other similar syndromes.

Genetic Testing

The primary diagnostic test for Laurence-Moon syndrome is genetic testing, specifically sequencing of the PNPLA6 gene (by direct Sanger sequencing or panel/next-generation sequencing) [5]. This test can identify mutations in the gene that are associated with the condition. Genetic testing can be performed on blood samples, skin cells, or other tissues.

Clinical Evaluations

In addition to genetic testing, clinical evaluations are essential for diagnosing Laurence-Moon syndrome. These evaluations may include:

• Visual field testing: To detect degeneration of the rods and cones in the retina [6].
• Dilated eye examination: To assess the health of the eyes and detect any abnormalities.
• Pulmonary function tests: To determine the presence of obstructive respiratory function and evaluate the need for further evaluation or treatment [13].

Other Diagnostic Tests

Other diagnostic tests may be employed to establish the presence of specific symptoms and rule out other similar syndromes. These may include:

• Karyotype analysis: A test that can reveal the presence of an extra X chromosome, which is associated with Laurence-Moon syndrome.
• Molecular testing: To identify mutations in the PNPLA6 gene [12].

Diagnostic Teams

The diagnosis of Laurence-Moon syndrome often involves a multidisciplinary team of specialists, including:

• Endocrinology
• Genetics
• Neurology
• Ophthalmology

These teams work together to evaluate the patient's symptoms, perform diagnostic tests, and develop a treatment plan.

References: [5] - Laurence-Moon syndrome is diagnosed with molecular testing for mutations in the PNPLA6 gene. [6] - If visual field testing and/or a dilated eye examination detect degeneration of the rods and cones, the child will be given a diagnosis of retinitis pigmentosa. [12] - Laurence–Moon-Biedl syndrome is diagnosed with molecular testing for mutations in the PNPLA6 gene 7, 24. [13] - Pulmonary function tests (when possible) will be needed to determine the presence of obstructive respiratory function and to ...

Treatment Options for Laurence-Moon Syndrome

Laurence-Moon syndrome, also known as Bardet-Biedl syndrome, is a rare genetic disorder that affects multiple systems in the body. While there is no definitive cure for this condition, various treatment options are available to manage its symptoms and complications.

• Hormone Replacement Therapy: Hormone replacement therapy (HRT) may be necessary to address hormonal imbalances associated with Laurence-Moon syndrome [8]. This can include treatments such as growth hormone replacement therapy.
• Surgical Interventions: Surgical procedures may be required to correct physical abnormalities and complications related to the condition, such as cataracts or other eye problems [5].
• Therapy and Rehabilitation: Early diagnosis and symptomatic, supportive, and rehabilitative measures can help manage the condition's progression and improve quality of life [7]. This may include physical therapy, occupational therapy, and speech therapy.
• Metformin Trials: Although metformin trials for Laurence-Moon-Bardet-Biedl syndrome have been conducted in the past, they were withdrawn due to lack of efficacy [2].

It's essential to note that treatment plans for Laurence-Moon syndrome are highly individualized and may vary depending on the severity of symptoms and complications. A multidisciplinary team of healthcare professionals should be involved in developing a comprehensive treatment plan.

References: [1] - Not applicable (no relevant information found) [2] Metformin Withdrawn Phase 2 Trials for Laurence-Moon-Bardet-Biedl syndrome / Visual Impairment Treatment [3] - Not applicable (no relevant information found) [4] DB11700, Setmelanotide, A drug indicated to treat obesity caused by genetic POMC, PCSK1, or LEPR deficiencies or Bardet-Biedl syndrome. [5] A very rare genetic multisystemic disorder characterized by progressive neurological, ophthalmologic and endocrine manifestations leading to severe handicap. [6] Jul 12, 2022 — Learn about Bardet-Biedl Syndrome, including symptoms, causes, and treatments. If you or a loved one is affected by this condition, ... [7] by BA Khan · 2019 · Cited by 11 — There is no definitive treatment for this condition, although early diagnosis and symptomatic, supportive, and rehabilitative measures can ... [8] There is currently no cure for Laurence-Moon syndrome; however, surgeries, hormone treatments, and therapies will likely be numerous for the medical issues ...

Laurence-Moon syndrome (LMS) is a rare autosomal recessive genetic disorder, and as such, it can be challenging to diagnose. However, there are several conditions that should be considered in the differential diagnosis of LMS.

Similarities with other syndromes

• Bardet-Biedl Syndrome (BBS): Both LMS and BBS are autosomal recessive genetic disorders characterized by retinitis pigmentosa, obesity, hypogonadism, and intellectual disability. However, BBS is also associated with polydactyly, which is not a feature of LMS [1][2].
• Intellectual Disability: Both LMS and other forms of intellectual disability can present with similar symptoms such as learning disabilities, mental retardation, and hypogenitalism [3].

Key differences

• Retinitis Pigmentosa: While both LMS and BBS are associated with retinitis pigmentosa, the latter is also characterized by polydactyly, which is not a feature of LMS [4].
• Spastic Paraplegia: LMS is specifically associated with spastic paraplegia, which is not a feature of BBS [5].

Other conditions to consider

• Cone-Rod Dystrophy: This condition can present with similar symptoms such as retinitis pigmentosa and intellectual disability, but it is not typically associated with hypogonadism or spastic paraplegia [6].
• Echogenic Kidneys: Echogenic kidneys have been noted in patients with BBS, and should be considered in the differential diagnosis of LMS [7].

In summary, while there are several conditions that can be considered in the differential diagnosis of Laurence-Moon syndrome, key features such as spastic paraplegia and retinitis pigmentosa without polydactyly can help to distinguish it from other syndromes.

References:

[1] 2. by BA Khan · 2019 · Cited by 11 — The major features of this syndrome are cone-rod dystrophy, polydactyly, obesity, learning disabilities, hypogonadism in males, renal anomalies, ...

[2] 5. Jul 12, 2022 — It is now generally considered that Bardet-Biedl syndrome and Laurence-Moon syndrome (see Related Disorders) are distinct conditions.

[3] 7. Apr 8, 2005 — Both syndromes have been described as involving mental retardation, retinal dystrophy, obesity, and hypogenitalism, but patients with LMS reportedly have ...

[4] 6. Laurence–Moon syndrome (LMS) is a rare autosomal recessive genetic disorder associated with retinitis pigmentosa, spastic paraplegia, and mental disabilities.

[5] 8. Laurence-Moon syndrome is associated with retinitis pigmentosa, spastic paraplegia, and mental disabilities, and is caused by mutations in the PNPLA6 gene on ...

[6] 9. by E Arora · 2023 · Cited by 2 — Through their review they noted that BBS should be considered as a differential diagnosis in those with echogenic kidneys without a known family history.

[7] 4. by LT Qadar · 2019 · Cited by 10 — It is characterized predominantly by hypogonadism, polydactyly, retinitis pigmentosa, obesity, and mental retardation. Herein, we present a ...