Cat Eye Syndrome Associated with Schizophrenia

Schizophrenia is a frequent and complex psychiatric disorder. Current neurobiological research in schizophrenia provides a wealth of information about structural, functional and genetic aspects of the disease [1]. Schizophrenia loci with evidence for linkage can be found on the following chromosal arms: 5q, 3p, 11q, 6p, 1q, 22q, 8p, 20p, 14p, and 2p-q [3]. Deletions, duplications, and translocations of proximal chromosome 22q have been associated with a number of syndromes and developmental abnormalities [6]. The majority of these rearrangements occur within the 22q11.2 region, termed 22q11 deletion syndrome, which is the most common of these. This deletion is associated with several syndromes, including DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes, and in almost all cases involves hemizygosity of the entire 3-Mb typically deleted region. Supernumery marker chromosomes with rearrangement in region 22q11.2 has been associated with cat-eye syndrome (CES) [2] [4]. Previously reported clinical findings for patients with CES include ocular coloboma, down slanting palpebral fissures, hypertelorism, preauricular pits and/or tags, cardiac malformations, renal malformations, anal atresia, and normal or only mildly retarded mental development.

A 25-year-old female patient, who was diagnosed to have CES associated with biocular coloboma, preauricular pits, hypaccusis, craniofacial malformations and skeletal anomalies was admitted to our hospital because of problems with auditory and coenesthetic hallucinations, bizarre delusions, paranoid ideas and suicidal ideation for the past 6 months. MRI scan showed Klippel-Feil sequence with spina bifida occulta and neuropsychological testing revealed no cognitive deficits. Corresponding to cat eye syndrome a cytogenetic analysis showed acrocentric chromosome fragments. Schizophrenia was diagnosed according to DSM-IV criteria and symptoms remitted after 4 weeks of treatment with olanzapine.

It has been observed that especially patients with velocardiofacial syndrome, which shows a deletion at 22q11, display increased incidence of schizophrenic psychosis [5]. Recent reports suggest a risk for the deletion at least one order of magnitude greater in schizophrenics than in the general population [5]. Thus it is probable that 22q11.2 contains loci that are associated with or contribute to the development of schizophrenia. Recent studies have confirmed this hypothesis, and a number of genes including catechol-O-methyltransferase within this region have been specifically implicated in predicting psychosis [3] [5].

In conclusion, we have reported the first case of schizophrenia in a patient with cat eye syndrome and underline the importance of the 22q11.2 region for the risk of development of the disease.

References

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