A forgotten lethal psychosis: a case report

Abstract

Homocystinuria due to cystathionine β-synthase deficiency is an inborn error of metabolism first described almost 50 years ago, which involves the accumulation of plasma homocysteine and other metabolites. Without early detection and appropriate treatment, common and sometimes lethal consequences include ocular abnormalities, osteoporosis, developmental delays, marfanoid phenotype, vascular disease, and mental retardation. Almost 50% of subjects develop a psychiatric disorder during their life, but only 2.8% present a psychiatric symptom as the initial manifestation. Among this group, psychotic disorders are infrequent. We describe the case of a 17-year-old boy presenting with a first episode psychosis and an unknown homocystinuria due to cystathionine β-synthase deficiency, which led to a lethal outcome.

Acute psychosis in an adolescent with undiagnosed homocystinuria

“…Previously reported patients showed different clinical phenotypes and a sparse or inconsistent responsiveness to vitamin supplementation (see Table 1). The case we describe, confirms the association between homocystinuria and early psychosis [4,[20][21][22][23].…”

“…The late occurrence of psychiatric symptoms has been reported in adults with homocystinuria [4,15,16]. An acute psychosis has been reported so far in three CBS deficiency patients [4,15,17], and a behavioral or psychiatric disorder as first symptom of homocystinuria occurs in only 2.8 % of patients [4,5]. Previously reported patients showed different clinical phenotypes and a sparse or inconsistent responsiveness to vitamin supplementation (see Table 1).…”

“…The most characterizing feature of homocystinuria (which is present in 80 % of cases) is represented by early subluxation of the lens with marked and progressive myopia [4][5][6]. Almost all reported cases also present cognitive impairment, a Marfan-like phenotype, osteoporosis and/ or cerebrovascular, cardiac thrombosis [4,7,8].…”

“…Almost all reported cases also present cognitive impairment, a Marfan-like phenotype, osteoporosis and/ or cerebrovascular, cardiac thrombosis [4,7,8]. Homocystinuria is generally considered a rare disease.…”

“…Epidemiology data show a variability in the prevalence of different mutations: some mutations, such as c.833 T > C (p.I278T) or c.1105C > T (p.R369C), are frequently found in Caucasians and in several European countries, with heterozygous rates crossing between 0.5 and 1.5 % of the population, corresponding to an incidence of predicted homozygosis rate between 1:17, 800 and 1:264,000 [11][12][13][14]. The late occurrence of psychiatric symptoms has been reported in adults with homocystinuria [4,15,16]. An acute psychosis has been reported so far in three CBS deficiency patients [4,15,17], and a behavioral or psychiatric disorder as first symptom of homocystinuria occurs in only 2.8 % of patients [4,5].…”