Minor physical anomalies and neurological soft signs in patients with schizophrenia and their siblings

Abstract Neurological soft signs (NSSs) and minor physical anomalies (MPAs) are consistently found at higher rates in individuals with schizophrenia compared to healthy controls. However, limited research has been conducted on these traits among the biological relatives of these patients. We aimed to identify the possible origins of these traits in schizophrenia by exploring them in patients with schizophrenia, their healthy siblings and normal controls. Ninety-six patients with schizophrenia, their 66 non-psychotic siblings and 52 healthy subjects were studied. Measures included the Neurological Evaluation Scale, a structured examination for detection of minor physical anomalies, stroop and verbal fluency tests for cognitive assessment, and scales for assessment of disease severity in patients; the Scale for the Assesment of Negative Symptoms and the Scale for the Assesment of Positive Symptoms. Increased rates of NSSs and high MPA scores were found in both the patients and their siblings as compared to normal controls. MPAs in several body regions were similar (eyes, ears, hands and feet) or correlated (innercanthal width and head circumference) between patients and their respective siblings. However, there was little similarity in palate and tongue anomalies between these subjects. These results suggest that NSSs and MPAs might represent two distinct markers of risk for schizophrenia. MPAs at different locations may also represent distinct pathological processes, such that palate and tongue abnormalities are more likely to represent non-familial rather than familial factors compared to other abnormalities.