Clinical features and molecular genetic analysis in a Turkish family with oral white sponge nevus

Abstract

BackgroundOral white sponge nevus (WSN) is a rare autosomal dominant benign condition, characterized by asymptomatic spongy white plaques. Mutations in Keratin 4 (KRT4) and 13 (KRT13) have been shown to cause WSN. Familial cases are uncommon due to irregular penetrance. Thus, the aim of the study was: a) to demonstrate the clinical and histopathological features of a three-generation Turkish family with oral WSN b) to determine whether KRT4 or KRT13 gene mutation was the molecular basis of WSN.Material and MethodsOut of twenty members of the family ten were available for assessment. Venous blood samples from six affected and five unaffected members and 48 healthy controls were obtained for genetic mutational analysis. Polymerase chain reaction was used to amplify all exons within KRT4 and KRT13 genes. These products were sequenced and the data was examined for mutations and polymorphisms.ResultsVarying presentation and severity of clinical features were observed. Analysis of the KRT13 gene revealed the sequence variant Y118D as the disease-causing mutation. One patient revealed several previously unreported polymorphisms including a novel mutation in exon 1 of the KRT13 gene and a heterozygous deletion in exon 1 of KRT4. This deletion in the KRT4 gene was found to be a common polymorphism reflecting a high allele frequency of 31.25% in the Turkish population.ConclusionsOral WSN may manifest variable clinical features. The novel mutation found in the KRT13 gene is believed to add evidence for a mutational hotspot in the mucosal keratins. Molecular genetic analysis is required to establish correct diagnosis and appropriate genetic consultation. Key words:White sponge nevus, leukokeratosis, oral mucosa, keratins, mutation.

White Sponge Nevus, a Rare but Important Entity

“…This feature is unique to WSN and is attributed to the ultrastructural concentration of tonofilaments around the nucleus. and variable expressivity [10]. Interestingly, all three of our patients had at least one or more family members affected, which correlates with other published cases [4,10,11].…”

“…WSN is a rare, hereditary disorder that affects approximately one in 200,000 people [9]. WSN is inherited as an autosomal dominant trait that exhibits an irregular penetrance and variable expressivity [10]. Interestingly, all three of our patients had at least one or more family members affected, which correlates with other published cases [4,10,11].…”

A Rare Clinical Case of Oral White Sponge Nevus and the Associated Challenges in Its Differential Diagnosis

“…However, various therapies have been developed to reduce the plaques of white sponge nevus, including beta-carotene, antibiotics (penicillin, azithromycin, etc. ), antihistamines, topical applications of inoic acid, and tetracycline mouthwashes, but without success [ 10 , 17 , 18 ]. The condition is benign, persist through whole life of the patient, and follow-up of the patient includes visits twice a year.…”

Exfoliative Cytology and Genetic Analysis for a Non-Invasive Approach to the Diagnosis of White Sponge Nevus: Case Series

“…The samples were analyzed the same day of the laboratory delivery, however the PreservCyt ® Solution allows sample storage for 30 days. Three non-invasive laboratory procedures were performed on each sample in order to verify the diagnosis of WSN: Papanicolau staining for cytomorphologic determination (ThinPrep), immune-cytopathology and Cell Block (CB) preparation [16,25].…”

“…OMIM stands for Online Mendelian Inheritance in Man, a catalog of human genes with monogenic inheritance (www.omim.org accessed on 14 April 2022). Patients discovering the presence of WSN while they are young adults or older pose difficult differential diagnosis, since some potentially malignant disorders can present as white patches [1,15,16]: conditions such as leukoplakia (especially its proliferative verrucous form) and oral lichen planus (in its plaque clinical form) must be excluded; furthermore, other benign white lesion must be excluded as leukoedema, lichenoid drug reaction, lupus erythematosus, cheek chewing, muscles and candidiasis [17][18][19]. In all the above-mentioned diseases, it is extremely important to reach the correct diagnosis and eventually start a suitable therapy.…”