Heterozygous Pathogenic Variants in SERPINB7 Potentially Associated With Concomitant Moyamoya Angiopathy and Nagashima‐Type Palmoplantar Keratoderma

ABSTRACT The authors present the first documented case of concomitant Nagashima‐type palmoplantar keratoderma and moyamoya angiopathy, identifying a novel gene as a potential link between rare dermatologic and cerebrovascular diseases. The subject of this case report was identified and clinically evaluated at the Neurological Institute of Children's Hospital Los Angeles. Written informed consent for clinical care, genetic testing, and participation in this case study was obtained. The patient initially presented with a history of several dermatologic conditions, including eczema, vitiligo, and Nagashima‐type palmoplantar keratoderma. Neurological examination and diagnostic imaging were strongly suggestive of moyamoya angiopathy, prompting a bilateral encephaloduroarteriomyosynangiosis. Singleton Clinical Exome Sequencing was subsequently performed, revealing pathogenic heterozygous variants in SERPINB7 . This study identifies SERPINB7 as a possible link between Nagashima‐type palmoplantar keratoderma and moyamoya angiopathy, indicating the pleomorphism of SERPINB7 ‐mediated changes in human disease. Further studies are warranted to investigate the function of SERPINB7 in endovascular tissue. Furthermore, the increasingly recognized association between autoimmune dermatologic disease and moyamoya may be mediated through genetic mechanisms, highlighting the importance of genetic testing in individuals with rare dermatologic and cerebrovascular disorders.