Autosomal recessive congenital ichthyosis due to PNPLA1 mutation in a golden retriever-poodle cross-bred dog and the effect of topical therapy.

BACKGROUND

Ichthyoses represent a genetically and phenotypically heterogeneous syndrome of abnormal epidermal cornification. Although the clinical presentation, histopathological findings and genetic cause of autosomal recessive congenital ichthyosis (ARCI) in golden retriever dogs have been well investigated, the optimal management of this disease remains uncharacterized.

OBJECTIVES

In this report we describe the beneficial effect of oral and topical fatty acids for management of a golden retriever and poodle cross-bred dog (goldendoodle) with ARCI due to a PNPLA1 (Patatin-like phospholipase domain containing 1) mutation.

CASE REPORT

A six-month-old, intact female, second generation golden retriever and poodle cross-bred dog presented with a history of generalized scaling since the age of 6 weeks. Histopathology showed diffuse, laminated-to-compact hyperkeratosis with a single small perinuclear vacuole in occasional stratum granulosum keratinocytes. Genetic testing revealed a homozygotic insertion/deletion mutation in the gene PNPLA1. Daily oral fatty acid supplementation and humectant rinse, following weekly moisturizing shampoo, resulted in only mild improvement after two months. Weekly application of a topical essential oils and fatty acid product was then added. Thirteen months after the initial presentation the dog exhibited a marked improvement in clinical signs. The temporal discontinuation of topical therapy resulted in the worsening of scaling, which improved again after resuming this combination.

CONCLUSIONS AND CLINICAL IMPORTANCE

To the best of the authors' knowledge, this is the first case report of ARCI with homozygous PNPLA1 mutation in a golden retriever-poodle cross-bred dog. The long-term combination of oral fatty acids and topical therapy appeared to be beneficial in this case.