Elevated nailfold plexus visibility aggregates in families and is associated with a specific negative symptom pattern in schizophrenia

Twenty-four individuals with schizophrenia and 28 of their first-degree biological relatives were studied using clinical scales, functional ratings, and neuropsychological tests. An assessment of Nailfold Plexus Visibility (NPV) was also performed on these individuals. In keeping with the literature, we found an increased prevalence of high NPV in our schizophrenia subjects relative to controls and community norms, and also found that high NPV patients had significantly more negative symptoms and poorer social functioning. Measures of negative symptoms indicative of the deficit syndrome did a better job of distinguishing high from low NPV subjects than did more broadly defined negative symptom indices. As predicted, the prevalence of high NPV in first-degree relatives of high NPV schizophrenia subjects was increased compared with relatives of low NPV schizophrenia subjects. These two relative groups did not differ on overall level of schizotypy symptoms or on negative symptom schizotypy indices. However, relatives of low NPV patients scored significantly higher on scales of positive symptom schizotypy. Overall, these results support the hypothesis that high NPV is a marker of risk for a distinct subtype of schizophrenia.