Laurence Moon Syndrome (LMS)

Association of ophthalmoplegia, pigmentary degeneration of retina (rod cone dystrophy), mental retardation, and cardiomyopathy.

Adipogenital-Retinitis Pigmentosa Syndrome; Laurence Syndrome

NB: Although Laurence-Moon-Bardet-Biedl syndrome has been split into two syndromes—LMS and Bardet-Biedl syndrome (rod cone dystrophy, obesity, postaxial polydactyly, learning disabilities and hypogenitalism)—many cases overlap.

First reported by ophthalmologist Laurence and surgeon Moon in 1866. Often confused with Bardet-Biedl Syndrome and called LMBB (Laurence-Moon-Bardet-Biedl syndrome).

Rare; more frequent in some places (Arabic population of Kuwait, among the Bedouins, often as Bardet-Biedl syndrome).

Autosomal recessive.

Not known. Pituitary gland is morphologically and immunohistologically normal.

Based on the clinical features: mental retardation, pigmentary retinopathy, hypogonadism, hypogenitalism, and spastic paraplegia. No obesity or polydactyly observed (as observed in Bardet-Biedl syndrome, with which the syndrome should not be confused even though it has strong similarities and overlap).

Symptoms usually occur in early or late childhood. Strabismus is often present and the cause of visual difficulties. Other clinical manifestations include night blindness, cataracts, and retinitis pigmentosa occurring during childhood. There is a decreased level of gonadotrophic hormone production because of hypogonadism, which contributes to delay of onset of puberty and development of secondary sex characteristics. Males usually are infertile and may develop pseudogynecomastia. Females have amenorrhea and fail to develop breasts. Other signs include mental retardation, ataxia, muscle rigidity, and spastic paraplegia. Renal disease is common because of abnormalities in the structure or function of the kidneys. In some rare cases, diabetes, congenital heart defects, and breathing problems may occur.

It is recommended to obtain a consultation in anesthesiology before elective surgery. Patients affected with morbid obesity will require complete evaluation of cardiovascular and respiratory functions prior to anesthesia and surgery. Pulmonary function tests (when possible) will be needed to determine the presence of obstructive respiratory function and to evaluate the possible need for postoperative mechanical ventilation. The investigation should include a complete cell blood count, glucose level, coagulation profile, and renal functions. The fasting period might require a longer time to allow complete gastric transit because these patients are more susceptible to maintain higher gastric volumes than others.

Anesthetic considerations are mostly influenced by the obesity status and the surgical procedure plan for the patient. In presence of severe obesity, use of invasive monitoring to ensure proper management of cardiovascular and respiratory functions might be appropriate. The potential for difficult direct laryngoscopy and tracheal intubation because of severe obesity and the risk of pulmonary aspiration complicate the management. The anesthetic management per se is not specific to the disease but rather to the anomalies associated with it. The presence of diabetes necessitates proper preoperative management and frequent measurement of glucose levels. Postoperative ventilatory support might be necessary to facilitate pain management and reduce risk of hypoventilation in these patients. The necessity for intermittent positive-pressure ventilation in the postoperative period should be organized ahead of the procedure.

No specific implications with this condition. Use of medication preventing increase of the plasma glucose level and administration of antibiotics in presence of cardiac defects are recommended.

Alström Syndrome: Photophobia, nystagmus, cone-rod dystrophy, dilated cardiomyopathy leading to congestive heart failure, acanthosis nigricans, short stature, hearing loss, hyperinsulinemia with insulin resistance, and renal tubular dysfunction.

Biemond Syndrome Type II: Mental retardation, coloboma, obesity, polydactyly, hypogonadism, hydrocephalus, and facial dysostosis; closely related to Laurence Moon syndrome (might be a variant).

Bardet-Biedl Syndrome: Rod-cone dystrophy, obesity, post-axial polydactyly, learning disabilities, and hypogenitalism; also closely related to Laurence Moon syndrome.

Prader-Labhart-Willi Syndrome: Diagnosed more often in males born after a prolonged, delayed birth in the breech position. Characterized by muscular weakness, failure to thrive during infancy, hypogonadism, dwarfism, and psychomotor retardation. Onset of age is between 1 and 3 years, when hyperphagia usually develops. Left uncontrolled, morbid obesity develops and leads to life-threatening heart and lung complications.

Borjeson-Forssman-Lehman Syndrome: Inherited as an X-linked dominant trait and characterized by unusual facial appearance, mental retardation, seizures, short stature, slowed sexual development, muscle weakness, and obesity.

Hypogonadotrophic Hypogonadism Syndrome (Secondary Hypogonadism): Disorder that affects the hypothalamus and production of gonadotropins. Characterized by the absence of secondary sexual characteristics.

Weiss Syndrome: Extremely rare disorder characterized by hypogonadism, mental retardation, obesity, and deafness.