Laurence-Moon-Biedl Syndrome (LMB) is an autosomal recessive disorder caused by a genetic mutation in the PDE6B gene. It is characterized by multiple physical and developmental abnormalities, including retinal dystrophy, polydactyly, obesity, hypogonadism, mental retardation, and kidney dysfunction (Dixit, Naik, & Nair, 2017). The syndrome is named after the three physicians who first described it in 1866: William Lawrence, William Moon, and Arthur Biedl.
The prevalence of LMB is estimated to be 1 in 100,000 to 250,000 (Bruno & Rappaport, 2018). While it is a rare disorder, it is important to recognize and diagnose it early as this can help optimize the management of the condition.
The onset of LMB is typically in childhood and the physical features often become more pronounced during puberty. Common physical findings include obesity, short stature, hypogonadism, polydactyly, and retinal dystrophy (Bruno & Rappaport, 2018). Mental retardation is also often present and can range from mild to severe. Other reported features include renal abnormalities, hearing loss, and congenital heart defects (Dixit et al., 2017).
The diagnosis of LMB is based on clinical findings and confirmed by genetic testing. The PDE6B gene encodes a subunit of the rod phototransduction cascade and its mutation results in impaired function of the photoreceptors in the retina (Bruno & Rappaport, 2018). As such, retinal dystrophy is a key feature in the diagnosis of this disorder.
The treatment of LMB is mainly supportive. Obesity can be managed with dietary and lifestyle modifications. Polydactyly can be managed with surgery if necessary. Mental retardation can be managed with speech and occupational therapy. Renal abnormalities may require dialysis or transplantation. Retinal dystrophy needs to be managed with regular monitoring and treatment initiated if necessary.
In conclusion, LMB is a rare disorder that affects multiple organs and systems. Early diagnosis and treatment can help optimize the management of this disorder.
References
Bruno, A., & Rappaport, E. (2018). Clinical features of Laurence-Moon-Biedl syndrome. Orphanet Journal of Rare Diseases, 13(1), 84. https://doi.org/10.1186/s13023-018-0736-3
Dixit, A., Naik, M., & Nair, S. (2017). Laurence-Moon-Biedl syndrome: A review. Indian Journal of Human Genetics, 23(1), 14–20. https://doi.org/10.4103/ijhg.IJHG_113_16