Dermatoglyphics and schizophrenia: A comprehensive review of neurodevelopmental biomarkers

Schizophrenia is a complex neuropsychiatric disorder marked by positive symptoms (hallucinations, delusions), negative symptoms (affective flattening, social withdrawal), and cognitive deficits. Its etiology reflects both strong genetic liability and environmental influences during critical stages of brain development. Dermatoglyphics, the study of epidermal ridge patterns on fingers, palms, and soles, forms between the 10^th and 16^th weeks of gestation, a key neurodevelopmental period. Because both the epidermis and central nervous system share an ectodermal origin, disturbances during this window may produce parallel alterations in ridge patterns and brain structure. Interest in anthropometric markers of psychiatric illness dates to the 19^th century, when theories of degeneracy proposed physical anomalies as signs of hereditary vulnerability. Although controversial, dermatoglyphics has recently re-emerged as a potential non-invasive biomarker for schizophrenia. This review synthesizes evidence on dermatoglyphic patterns in schizophrenia, emphasizing twin studies, comparisons with bipolar disorder, and integration with related developmental anomalies such as minor physical anomalies and somatotype. A structured search of PubMed and Scopus (January 2004 to December 2024) identified 83 eligible studies. Inclusion criteria encompassed original human research, reviews, or meta-analyses on dermatoglyphics in schizophrenia or related psychotic disorders, while excluding animal studies, non-quantitative case reports, and non-English papers without translation. Consistent findings include reduced total ridge counts, increased fluctuating asymmetry, and greater prevalence of abnormal palmar flexion creases among individuals with schizophrenia. Twin designs show anomalies are more frequent in affected co-twins, even among monozygotic pairs, underscoring prenatal environmental effects. Comparative work suggests schizophrenia and bipolar disorder share some but not all dermatoglyphic alterations, offering potential diagnostic value. Dermatoglyphic analysis is stable, inexpensive, and non-invasive, supporting its promise as an adjunctive biomarker of neurodevelopmental disruption. However, methodological variability and limited standardization currently restrict clinical application. Future research should harmonize measurement techniques and integrate genomic and neuroimaging correlates.