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Wednesday, Dec 03, 2008 | 02:58 PM
Madisons Foundation - Moms And Dads In Search Of Needed Support
Laurence-Moon Syndrome
Adipogenital-Retinitis Pigmentosa Syndrome, Bardet-Biedl Syndrome,
Laurence-Moon-Biedle Syndrome,
Monday, 05 September 2005
Last Updated Monday, 05 September 2005
What
Laurence-Moon syndrome (LMS), which was until very recently believed to be a separate disorder from Bardet-Biedl syndrome (BBS), is a rare, inherited disorder characterized by hypogonadism (the decreased production of sex hormones), retinitis pigmentosa (progressive loss of vision due to retinal problems), mental retardation, kidney abnormalities, obesity, spasticity of the lower body (paralysis of muscles with involuntary muscle contractions), and/or polydactyly (presence of extra digit on hands or feet).Who
LMS occurs with an incidence of approximately 1 in 160,000 people in the general population. In the Arab population of Kuwait, the incidence increases to 1 in 65,000, while in Newfoundland, the incidence is 1 in 18,000. It is more likely to appear in families and communities where consanguinity (blood relationships) is common. Males and females are equally affected.Signs and Symptoms
The primary features of LMS are: decline in vision (due to retinitis pigmentosa), mental retardation, and abnormal reproductive development (due to low sex hormone levels) all usually presenting in childhood. In addition, patients frequently have obesity with polydactyly or muscle spasticity—usually not both. Historically, what is now designated as LMS was divided into two separate conditions: BBS, which included obesity and polydactyly, and classic LMS, which featured spasticity. However, recently published research suggests that BBS is essentially the same condition as classic LMS, but with variable expression of symptoms. Other conditions frequently associated with the current definition of LMS include diabetes mellitus, high blood pressure, kidney abnormalities, liver and gall bladder problems, reproductive abnormalities, psychiatric illness, hormone disturbances, short stature, developmental delay, neurological deficits such as impaired speech and coordination, abnormal facial features, gastrointestinal disturbances, asthma, congenital heart disease, and seizures.Possible Causes
LMS is an autosomal recessive disorder caused by any of at least 8 possible mutations in genes located on several different chromosomes. An autosomal recessive disorder means that an affected child inherited one abnormal copy of the gene from each parent (parents are “carriers”). The expression of LMS is highly variable due to the many different types of gene abnormalities. Collectively, the genes responsible are known as the BBS genes, and they code for proteins involved in the maturation of almost every organ system—hence the widespread complications of the disorder.Diagnosis
The diagnosis of LMS is made based primarily on recognition of the characteristic signs of hypogonadism, retinal degeneration, mental retardation, obesity, and impaired renal function. Blood tests looking at kidney function and sex hormone levels may be ordered by your doctor. Referral to an ophthalmologist is also important for detection of retinal changes. At present only a few laboratories perform genetic analysis to make a definitive diagnosis from blood tests.Treatment
While there is no cure for LMS, treatment is primarily focused on supportive care for each related organ dysfunction. For example, patients with kidney problems that progress to end-stage renal disease may receive dialysis and ultimately kidney transplants as a treatment option. Likewise, developmental and neurological delays may be minimized by early rehabilitation programs in speech, language, and motor skills. Care requires coordination with many specialists in the fields of endocrinology, ophthalmology, nephrology, and occupational/physical therapy.Prognosis
Patients with LMS are able to live fairly long lives, barring serious complications and with close monitoring of all systems. The early deaths (median age 46) that have occurred from LMS were the result of untreatable disease-related conditions, such as cardiovascular complications, kidney failure, or infection. Of the majority of patients who live to adulthood, 91% of them will become blind from retinitis pigmentosa, usually by the age of 18. Early clinical diagnosis is essential for education and physical therapy interventions, which may help to minimize difficulties with neurological and mental function that usually occur with LMS.Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.Weblinks
Laurence-Moon-Bardet-Biedl Society
Very helpful website of charity that produces newsletters, an annual family conference, information booklets, and other resources for patients and families with LMS. Includes links to research and other websites.
Foundation Fighting Blindness
Information, clinical trials, FAQs, and chat room for patients and families with blindness-causing disorders, including retinitis pigmentosa.
Blind Children’s Fund
Information, resources, advocacy, and intervention services for parents of infants and children who are blind or visually impaired.
Third Aid
Free support website that provides online communities for many conditions, including LMS. Offers way for patients and caregivers to share their advice and experiences.
Family Village
Lots of useful links to support groups and web pages.
Laurence-Moon-Bardet-Biedl Network
Touching stories and contact information for parents.