Prader-Willi Syndrome

SIR: Prader-Willi syndrome is a chromosomal disorder that was first described by Langdon Down 1 in 1887 and was reported by Prader et al. 2 in 1956. They reported a series of patients with mental retardation, obesity, and hypogonadism.

In 1981, Ledbetter et al. 3 identified deletions of genes in the proximal arm of the paternal chromosome 15. Loss of gene material at the maternal chromosome 15 results in Angleman Syndrome. This pattern of inheritance—when expression of a gene depends on whether it is inherited from the father or the mother—is called imprinting. 4

Prader-Willi syndrome is the first human disease attributed to genomic imprinting. 4 In the United States, rate of prevalence of the syndrome has been reported to be 1 in 16,000. 1 Differences in prevalence between racial groups, sex, and age have not been reported. 1 Although the syndrome is best known for its food-related characteristics, including hyperphagia and obesity due to decreased perception of satiety secondary to hypothalamic abnormalities, 6 , 7 it also involves other non-food-related characteristics, such as cognitive dysfunction, academic weakness, and behavioral problems. 5 , 7 , 8

Some reports have noted that behavioral problems increase in adolescence and adulthood years because of growing psychosocial stresses. 9 Often, these maladaptive behaviors pose multiple challenges to the clinicians and heighten the stress of the patient’s family.

Case Report

A 26-year-old man was diagnosed with Prader-Willi syndrome. Despite his mild mental retardation and delayed developmental milestones, he finished 12th grade of special education.

His elderly parents were unable to provide the essential care for his condition and requested housing support in form of group home setting. The patient was unable to cope with the changes and responded with disruptive behavior that led to his first psychiatric admission.

On the day of admission, the patient became agitated with little provocation and attempted to break the fish tank in his house; when his mother interfered, he threatened her.

In the emergency room, he appeared with the following physical features: obesity (weight: 285 pounds, height: 5 ft), a round face with full checks, narrow nasal bridge, down-turned mouth with thin upper lip, small hands and feet, and undescended testicles.

His characteristic profile included compulsive eating, hoarding food, argumentativeness, stubbornness, irritability, aggressive behavior, skin picking, and sleep apnea.

His electrocardiogram, complete blood count, and blood chemistry were within normal levels.

On interview, the patient was uncooperative, loud, screaming, punching the walls, slamming the doors, and demanding to leave the hospital. He denied suicidal and homicidal ideation. No psychotic features were elicited. He was medicated and was admitted to the developmental delay unit in a different hospital.

Comment

Unfortunately, diagnosis of Prader-Willi syndrome is overlooked, despite the clinical criteria. Management of the syndrome requires a multidisciplinary approach; treatment implications involve medical and dietary management as well as psychiatric intervention.