MPAs may reflect genetic risk for schizophrenia

By Mark Cowen, Senior medwireNews Reporter

Minor physical anomalies (MPAs) are more common in schizophrenia patients and their unaffected siblings than in mentally healthy individuals without a family history of the disorder, research shows.

Indeed, Leila Gassab and colleagues from the University of Monastir in Tunisia found that schizophrenia patients had a significantly higher rate of MPAs than their siblings, who, in turn, had a significantly higher rate of MPAs than mentally healthy controls.

"MPAs appear to reflect the degree of psychosis proneness," comment the researchers in Comprehensive Psychiatry.

The team assessed 93 patients with schizophrenia, 59 of their mentally healthy siblings, and 71 age- and gender-matched mentally healthy controls for the presence of MPAs in six body areas (head, eyes, ears, mouth, hands, and feet) using a standardized scale derived from the Waldrop Scale.

Patients with schizophrenia were also assessed using the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF), and the Clinical Global Impression-Severity (CGI-S).

The researchers found that the prevalence of MPAs was significantly higher in schizophrenia patients than in siblings and controls, at 60.2% versus 33.9% and 12.7%, respectively. The difference between siblings and controls was also significant.

Schizophrenia patients also had significantly higher total MPA scores on the Waldrop-derived scale than siblings and controls, at 4.6 versus 3.0 and 1.9, respectively. Again, the difference in MPA score between siblings and controls was significant.

In patients with schizophrenia, MPA scores were significantly and negatively correlated with age at disease onset and age at first hospitalization, and positively correlated with number of hospitalizations.

There was also a significant positive correlation between MPA scores and PANSS total and negative subscale scores, and CGI severity score. However, no significant correlation was found between MPA score and GAF score.

"The increased rates of MPAs, found in the non-ill siblings of patients with schizophrenia serve as a reminder that the families of patients manifest a range of 'vulnerability' characteristics, which are not 'sufficient' for the later development of schizophrenia," comment Gassab et al.

They conclude: "MPAs should be considered as markers of a generalized early neuromaldevelopment, and as markers of a specific [severe] clinical subtype of schizophrenia."

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