- 2025, Volume 83 - Number 3
- Published: October 1, 2025
Punctate palmoplantar keratoderma type I: the clinical and genetic features of two family members with AAGAB gene mutation
Lanyu Sun 1, Leonor Lopes 1, Pedro de Vasconcelos 2, Luís Soares-de-Almeida 3, Gabriel Miltenberger-Miltenyi 4, Joana F. Ferreira 5, Paulo L. Filipe 6
1 Serviço de Dermatologia, Unidade Local de Saúde Santa Maria, Lisbon, Portugal; 2 Dermatology and Venereology Department, Hospital de Santa Maria, Unidade Local de Saúde Santa Maria, Lisbon, Portugal; 3 Dermatology and Venereology Department, Hospital de Santa Maria, Unidade Local de Saúde Santa Maria; Dermatology and Venereology University Clinic, Faculty of Medicine, University of Lisbon; Dermatology Research Unit, iMM João Lobo Antunes, University of Lisbon. Lisbon, Portugal; 4 IMM João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; 5 Unidade de Saúde Familiar Monte Crasto, Unidade Local de Saúde Santo António Porto, Portugal; 6 Department of Dermatology and Venereology, Unidade Local de Saúde Santa Maria; Faculdade de Medicina da Universidade de Lisboa, Dermatology Clinic. Lisbon, Portugal
Lanyu Sun, Leonor Lopes, Pedro de Vasconcelos, Luís Soares-de-Almeida, Gabriel Miltenberger-Miltenyi, Joana F. Ferreira, Paulo L. Filipe
La información completa de afiliaciones y autor de correspondencia está disponible en la versión original en PDF.
*Correspondence: Gabriel Miltenberger-Miltenyi, Email not available
Abstract
Hereditary punctate palmoplantar keratoderma type I (PPPK1) is a rare autosomal dominant disorder characterized by hyperkeratotic papules on the palms and soles, typically appearing in adolescence but occasionally manifesting later in life. We describe two family members, an African woman (61 years old) and her daughter (29 years old), presenting with multiple asymptomatic hyperkeratotic papules on the palms and soles. Histopathology revealed orthohyperkeratosis, acanthosis, hypergranulosis, and elongated rete ridges. Genetic analysis identified a heterozygous c.535+1G>A mutation in the AAGAB gene. Despite topical salicylic acid, urea, and tretinoin treatment, only minimal improvement was observed. PPPK1 pathogenesis involves genetic factors, with AAGAB being a major contributor, although other loci may be implicated. These cases highlight the phenotypic variability and delayed disease onset in some individuals, underscoring the need for further investigation into the underlying genetic mechanisms and effective treatment strategies.
