Is punctate palmoplantar keratoderma type 1 associated with malignancy? A systematic review of the literature.

BACKGROUND: An association between punctate palmoplantar keratoderma type 1 (PPPK1) and malignancy has been proposed for decades. Some authors suggest that individuals with PPPK1 should undergo screening for various types of malignancies while others caution that an association is not well-established. In this systematic review, we summarized and evaluated the current evidence for a possible association between PPPK1 and malignancy. METHODS: The review was conducted along PRISMA guidelines. The search used Embase, MEDLINE, Scopus, and the Human Gene Mutation Database up to March 2022. All studies reporting on individuals with the diagnosis of PPPK1 with or without history of malignancy were included. Two authors screened for eligible studies, extracted predefined data, and performed a quality assessment. RESULTS: Of 773 studies identified, 45 were included. Most studies were reports on single families (24 of 45 studies) or multiple families (10 of 45 studies). The number of index cases with PPPK1 across all included studies was 280, and when family members reported with PPPK1 were added, a total of 817 individuals were identified. Overall, 23 studies reported on individuals with PPPK1 with a history of malignancy, whereas 22 studies reported on individuals with PPPK1 without a history of malignancy. Although the extracted data were not considered to be of sufficient quality to synthesize and answer our research question, the review did not confirm an association between PPPK1 and malignancy. CONCLUSION: This review shows that there is a lack of well-designed studies on this topic to conclude whether individuals with PPPK1 have an increased risk of malignancy. Based on the present literature, however, we could not confirm an association between PPPK1 and malignancy and find it highly questionable if patients with PPPK1 should be offered surveillance for malignancies.

Disease pattern in Danish patients with Peutz-Jeghers syndrome.

PURPOSE: In this paper, we aimed to collect genetic and medical information on all Danish patients with Peutz-Jeghers syndrome (PJS), in order to contribute to the knowledge of phenotype and genotype. Peutz-Jeghers syndrome is a hereditary syndrome characterized by multiple hamartomatous polyps in the GI tract, mucocutaneous pigmentations, and an increased risk of cancer in the GI tract and at extraintestinal sites. Over 90 % of patients harbour a pathogenic mutation in STK11. METHODS: Based on the Danish Pathology Data Bank, the Danish National Patient Register, as well as information from relevant departments at Danish hospitals, we identified patients and collected clinical and genetic information. RESULTS: We identified 43 patients of which 14 were deceased. The prevalence was estimated to be ∼1 in 195,000 individuals. The median age at first symptom was 27.5 with invagination of the small bowel as the most frequent presenting symptom. We noted 18 occurrences of cancer at various anatomical sites, including a case of thyroid cancer and penile cancer. Eight of the deceased patients had died of cancer. Eighteen different mutations in STK11 had been detected in 28 patients. CONCLUSION: This is the first comprehensive study of patients with Peutz-Jeghers syndrome in the Danish population identified from nationwide registers and databases. We have demonstrated that the expressivity of Peutz-Jeghers syndrome varies greatly among the patients, even within the same families, underlining the great phenotypic spectrum. Patients with PJS should be offered surveillance from childhood in order to prevent morbidity and reduce mortality.

JP-HHT phenotype in Danish patients with SMAD4 mutations.

Patients with germline mutations in SMAD4 can present symptoms of both juvenile polyposis syndrome (JPS) and hereditary hemorrhagic telangiectasia (HHT): the JP-HHT syndrome. The complete phenotypic picture of this syndrome is only just emerging. We describe the clinical characteristics of 14 patients with SMAD4-mutations. The study was a retrospective, register-based study. SMAD4 mutations carriers were identified through the Danish HHT-registry, the genetic laboratories - and the genetic departments in Denmark. The medical files from relevant departments were reviewed and symptoms of HHT, JPS, aortopathy and family history were noted. We detected 14 patients with SMAD4 mutations. All patients had polyps removed and 11 of 14 fulfilled the diagnostic criteria for JPS. Eight patients were screened for HHT-symptoms and seven of these fulfilled the Curaçao criteria. One patient had aortic root dilation. Our findings support that SMAD4 mutations carriers have symptoms of both HHT and JPS and that the frequency of PAVM and gastric involvement with polyps is higher than in patients with HHT or JPS not caused by a SMAD4 mutation. Out of eight patients screened for aortopathy, one had aortic root dilatation, highlighting the need for additional screening for aortopathy.

Acromelic frontonasal dysostosis and ZSWIM6 mutation: phenotypic spectrum and mosaicism.

Acromelic frontonasal dysostosis (AFND) is a distinctive and rare frontonasal malformation that presents in combination with brain and limb abnormalities. A single recurrent heterozygous missense substitution in ZSWIM6, encoding a protein of unknown function, was previously shown to underlie this disorder in four unrelated cases. Here we describe four additional individuals from three families, comprising two sporadic subjects (one of whom had no limb malformation) and a mildly affected female with a severely affected son. In the latter family we demonstrate parental mosaicism through deep sequencing of DNA isolated from a variety of tissues, which each contain different levels of mutation. This has important implications for genetic counselling.

National mutation study among Danish patients with hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and visceral arteriovenous malformations (AVM). The clinical diagnosis of HHT is based on the Curaçao criteria. About 85% of HHT patients carry mutations in the ENG, ACVRL1 or SMAD4 genes. Here, we report on the genetic heterogeneity in the Danish national HHT population and address the prevalence of pulmonary arteriovenous malformations (PAVM). Probands of 107 apparently unrelated families received genetic testing, including sequencing and multiplex ligation-dependent probe amplification (MLPA) analyses of ENG, ACVRL1 and SMAD4. These 107 families included 320 patients confirmed to have HHT either clinically or genetically. In 89% of the probands (n=95), a mutation was identified. We detected 64 unique mutations of which 27 (41%) were novel. Large deletions were identified in ENG and ACVRL1. The prevalence of PAVM was 52.3% in patients with an ENG mutation and 12.9% in the ACVRL1 mutation carriers. We diagnosed 80% of the patients clinically, fulfilling the Curaçao criteria, and those remaining were diagnosed by genetic testing. It is discussed when to assign pathogenicity to missense and splice site mutations. The adding of an extra criterion to the Curaçao criteria is suggested.

Duplication of 7q36.3 encompassing the Sonic Hedgehog (SHH) gene is associated with congenital muscular hypertrophy.

Muscular hypertrophy is a very rare finding on foetal ultrasonography. We present a case with recurrent muscular hypertrophy, liver enlargement and polyhydramnios in two pregnancies. One pregnancy was terminated due to suspicion of a storage disease, whereas the other led to delivery of a boy with muscular hypertrophy and mildly retarded psychomotor development. Array-CGH identified a small duplication of 7q36.3 including the Sonic Hedgehog (SHH) gene in both the aborted foetus and the live born male sib. Neither of the parents carried the 7q36.3 duplication. The consequences of overexpression of SHH in humans are not elucidated, but animal studies have suggested its importance in muscular hypertrophy. We suggest that the clinical findings in the presented case might be explained by the duplication and presumed overexpression of SHH.

Skin manifestations in a case of trisomy 16 mosaicism.

We present a 48-year-old man with unilateral dermatological manifestations including hypertrichosis, telangiectasia, hyperkeratosis and hyperpigmentation. Additional findings included skeletal abnormalities and left-sided hearing loss. Skin biopsies showed changes characteristic of porokeratosis. Fibroblast karyotyping from affected skin demonstrated trisomy 16 mosaicism, in contrast to the normal karyotype in unaffected skin and blood lymphocytes. The possible role of trisomy 16 in porokeratosis is discussed.