Segmental basaloid follicular hamartomas derive from a post-zygotic SMO p.L412F pathogenic variant and express hair follicle development-related proteins in a pattern that distinguish them from basal cell carcinomas.

Basaloid follicular hamartomas (BFH) are benign small basaloid skin tumors that can present as solitary or multiple lesions. Congenital BFH lesions arranged in a segmental distribution have been described, suggesting they derive from a somatic post-zygotic mutational event. Previously, BFH were described in Happle-Tinschert syndrome, which results from a post-zygotic SMO variant and is characterized by segmental BFH with variable involvement of the teeth, skeleton, and central nervous system. Here, we describe two patients with isolated segmental BFH and no systemic involvement. Paired whole exome sequencing of BFH and normal tissue revealed a pathogenic SMO c.1234 C>T, p.L412F variant restricted to BFH tissue. We characterized the proliferation index and expression of Hedgehog and Wnt/beta-catenin pathway related proteins in segmental BFH compared to sporadic basal cell carcinomas (BCCs) and found that segmental BFH had a lower proliferation index. Although segmental BFH expressed a similar level of Gli-1 compared to BCCs, levels of LEF-1 and SOX-9 expression in BFH were weaker for both and patchier for LEF-1. Our results show that a somatic SMO activating variant causes segmental BFH. Since these patients are prone to developing BCCs, differences in SOX9, LEF1, and Ki-67 expression can help distinguish between these two basaloid lesions.

Exome sequencing identifies a homozygous C5orf42 variant in a Turkish kindred with oral-facial-digital syndrome type VI.

Oral-facial-digital syndrome type VI (OFDVI) is a rare ciliopathy in the spectrum of Joubert syndrome (JS) and distinguished from other oral-facial-digital syndromes by metacarpal abnormalities with central polydactyly and by a molar tooth sign on cranial MRI. Additional characteristic features include short stature, micrognathia, posteriorly rotated low-set ears, hypertelorism, epicanthal folds, broad nasal tip, tongue hamartoma, upper lip notch, intraoral frenula, cleft lip/palate, and renal anomalies. Recently, novel mutations in C5orf42 were identified in 9 out of 11 OFDVI families. In a subsequent study C5orf42 was found to be mutated in only 2 out of 17 OFDVI probands while 28 patients with a pure JS phenotype also had pathogenic mutations of C5orf42. We report on two affected cousins diagnosed with OFDVI who were born from first degree cousin marriages. Whole exome sequencing (WES) identified a homozygous predicted damaging missense mutation (c.4034A > G; p.Gln1345Arg) in the C5orf42 gene. Our data contribute to the evidence that C5orf42 is one of the causative genes for OFDVI.

C5orf42 is the major gene responsible for OFD syndrome type VI.

Oral-facial-digital syndrome type VI (OFD VI) is a recessive ciliopathy defined by two diagnostic criteria: molar tooth sign (MTS) and one or more of the following: (1) tongue hamartoma (s) and/or additional frenula and/or upper lip notch; (2) mesoaxial polydactyly of one or more hands or feet; (3) hypothalamic hamartoma. Because of the MTS, OFD VI belongs to the "Joubert syndrome related disorders". Its genetic aetiology remains largely unknown although mutations in the TMEM216 gene, responsible for Joubert (JBS2) and Meckel-Gruber (MKS2) syndromes, have been reported in two OFD VI patients. To explore the molecular cause(s) of OFD VI syndrome, we used an exome sequencing strategy in six unrelated families followed by Sanger sequencing. We identified a total of 14 novel mutations in the C5orf42 gene in 9/11 families with positive OFD VI diagnostic criteria including a severe fetal case with microphthalmia, cerebellar hypoplasia, corpus callosum agenesis, polydactyly and skeletal dysplasia. C5orf42 mutations have already been reported in Joubert syndrome confirming that OFD VI and JBS are allelic disorders, thus enhancing our knowledge of the complex, highly heterogeneous nature of ciliopathies.

A mutation in the mucosal keratin K4 is associated with oral white sponge nevus.

White sponge nevus (WSN) is a benign autosomal dominant disorder which affects non-cornifying stratified squamous epithelia (MIM 193900) (ref. 1). Phenotypically it presents as white 'spongy' plaques (oral leukokeratoses), most commonly in the mouth but also reported in the esophagus and anogenital mucosa. Histologically, the plaques show evidence of hyperproliferation, acanthosis and tonofilament aggregation. These types of pathogenic changes are characteristic of many of the epidermal keratin disorders. Keratins are expressed in pairs by epithelial cells in a tissue and cell specific manner. The major differentiation specific keratins of the buccal mucosa, nasal, esophageal and anogenital epithelia are K4 and K13 (ref. 7). The tissue distribution and nature of the lesions in patients affected by WSN suggested that mutations in K4 and/or K13 might be responsible for this disorder. We have now confirmed this hypothesis and report here a three base-pair (bp) deletion in the helix initiation peptide of K4 in affected members from two families with this condition.

Multifocal demyelinating motor neuropathy and hamartoma syndrome associated with a de novo PTEN mutation.

OBJECTIVE: To describe a patient with a multifocal demyelinating motor neuropathy with onset in childhood and a mutation in phosphatase and tensin homolog (PTEN), a tumor suppressor gene associated with inherited tumor susceptibility conditions, macrocephaly, autism, ataxia, tremor, and epilepsy. Functional implications of this protein have been investigated in Parkinson and Alzheimer diseases. METHODS: We performed whole-exome sequencing in the patient's genomic DNA validated by Sanger sequencing. Immunoblotting, in vitro enzymatic assay, and label-free shotgun proteomic profiling were performed in the patient's fibroblasts. RESULTS: The predominant clinical presentation of the patient was a childhood onset, asymmetric progressive multifocal motor neuropathy. In addition, he presented with macrocephaly, autism spectrum disorder, and skin hamartomas, considered as clinical criteria for PTEN-related hamartoma tumor syndrome. Extensive tumor screening did not detect any malignancies. We detected a novel de novo heterozygous c.269T>C, p.(Phe90Ser) PTEN variant, which was absent in both parents. The pathogenicity of the variant is supported by altered expression of several PTEN-associated proteins involved in tumorigenesis. Moreover, fibroblasts showed a defect in catalytic activity of PTEN against the secondary substrate, phosphatidylinositol 3,4-trisphosphate. In support of our findings, focal hypermyelination leading to peripheral neuropathy has been reported in PTEN-deficient mice. CONCLUSION: We describe a novel phenotype, PTEN-associated multifocal demyelinating motor neuropathy with a skin hamartoma syndrome. A similar mechanism may potentially underlie other forms of Charcot-Marie-Tooth disease with involvement of the phosphatidylinositol pathway.

PTCH1 Germline Mutations and the Basaloid Follicular Hamartoma Values in the Tumor Spectrum of Basal Cell Carcinoma Syndrome (NBCCS).

BACKGROUND/AIM: Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominantly inherited disorder characterized by multiple basal cell carcinomas (BCC), odontogenic tumors and various skeletal anomalies. Basaloid follicular hamartomas (BFHs) constitute rare neoplasms that can be detected in sporadic and familial settings as in the Basaloid Follicular Hamartoma Syndrome (BFHS). Although BFHS shares clinical, histopathological and genetic overlapping with the NBCCS, they are still considered two distinctive entities. The aim of our single-institution study was the analysis of a cohort of PTCH1-mutated patients in order to define clinical and biomolecular relationship between NBCCS and BFHs. MATERIALS AND METHODS: In our study we evaluated PTCH1 gene-carrier probands affected by NBCCS to detect the incidence of BFHs and their correlation with this rare syndrome. RESULTS: Among probands we recognized 4 patients with BFHs. We found 15 germline PTCH1 mutations, uniformly distributed across the PTCH1 gene. Six of them had familial history of NBCCS, two of them were novel and have not been described previously. CONCLUSION: NBCCS and BFHS may be the same genetic entity and not two distinctive syndromes. The inclusion of BFH in the NBCCS cutaneous tumor spectrum might be useful for the recognition of misdiagnosed NBCCS cases that could benefit from tailored surveillance strategies.

Autosomal dominant primary hyperparathyroidism and jaw tumor syndrome associated with renal hamartomas and cystic kidney disease: linkage to 1q21-q32 and loss of the wild type allele in renal hamartomas.

Hereditary hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disease (OMIM 145001) that has recently been mapped to chromosomal region 1q21-q32 (HRPT2). Here we report two families with HPT-JT syndrome in which adult renal hamartomas or cystic kidney disease were prominent associated features, possibly representing a new phenotypic variant of the HPT-JT syndrome. In the first family, renal lesions were present in five out of six affected individuals, whereas HPT and JT were seen in four and two cases, respectively. In the second family, JT was found in three of the five affected individuals and two affected members also exhibited polycystic kidney disease. The possibility of the latter cosegregating as a separate autosomal dominant gene can not be ruled out. A sex-dependent penetrance of primary HPT, resulting in predominantly male-affected cases was evident in the two families. Twenty microsatellite markers in the HRPT2 region were typed, in addition to markers in the multiple endocrine neoplasia (MEN) types 1 and 2 regions at 11q13 and 10q11. The disease in these two kindreds was linked to five markers in the 1q21-q32 region (logarithm-of-odds scores: 3.2-4.2), whereas linkage to the MEN1 and MEN2 regions was excluded. Meiotic recombinations detected in affected individuals placed the locus telomeric of D1S215, thus narrowing the HRPT2 region from > 60 to approximately 34 centimorgans. Loss of heterozygosity was studied in seven renal hamartomas from two affected individuals in the first family, as well as in a jaw tumor and a parathyroid tumor from the second family. All renal hamartomas showed loss of heterozygosity at the 1q21-q32 region. The losses invariably involved the wild type allele derived from the unaffected parent, suggesting the inactivation of a tumor suppressor gene in this region.

Cowden's disease: a further indication for prophylactic mastectomy.

Cowden's disease (multiple hamartoma syndrome) is a syndrome involving abnormalities of multiple organ systems. Transmitted in an autosomal dominant pattern, it carries a high frequency of mammary carcinoma in early middle age in affected women. The hyperkeratotic cutaneous and gingival markers of the disease are its principal overt manifestations. Prophylactic bilateral total mastectomy with optional immediate reconstruction is recommended for women Cowden's disease. An illustrative family with the disease is presented in which one affected young woman was found to have invasive mammary carcinoma with regional metastasis at the time of prophylactic mastectomy.

Multiple facial angiofibromas and collagenomas in patients with multiple endocrine neoplasia type 1.

OBJECTIVES: To evaluate patients with multiple endocrine neoplasia type 1 (MEN 1) for cutaneous manifestations. DESIGN: Survey during a 3-year period. SETTING: The National Institutes of Health, a tertiary referral research hospital in Bethesda Md. PATIENTS: A consecutive sample of 32 individuals with previously diagnosed MEN1 who were not preselected for the presence of skin lesions were examined for cutaneous abnormalities. None of the patients or family members were diagnosed as having tuberous sclerosis. INTERVENTIONS: Lesions were identified by clinical appearance, photographed, and confirmed histologically. MAIN OUTCOME MEASURE: To determine the frequency of skin lesions in patients with MEN1. RESULTS: Multiple facial angiofibromas were observed in 28 (88%) of the patients with MEN1, with 16 patients (50%) having 5 or more. Angiofibromas were clinically and histologically identical to those in individuals with tuberous sclerosis. Collagenomas were observed in 23 patients (72%). Also observed were cafe au lait macules in 12 patients (38%), lipomas in 11 patients (34%), confetti-like hypopigmented macules in 2 patients (6%), and multiple gingival papules in 2 patients (6%). CONCLUSIONS: Multiple angiofibromas, collagenomas, lipomas, confetti-like hypopigmented macules and multiple gingival papules are cutaneous manifestations of MEN1 and should be looked for in both family members of patients with MEN1 and individuals with hyperparathyroidism of other MEN1-associated tumors. Multiple angiofibromas can no longer be considered pathognomonic for tuberous sclerosis. The observation of angiofibromas in individuals without tuberous sclerosis necessitates further biochemical testing for MEN1.

Nevoid basal cell carcinoma syndrome.

Nevoid basal cell carcinoma syndrome has as its hallmarks such diverse manifestations as numerous cutaneous basal cell cancers and epidermal cysts, palmar and plantar pits, keratocysts of the jaw, calcified dural folds, various skeletal anomalies, cleft lip and/or palate, and various other neoplasms or hamartomas. Inheritance is autosomal dominant. The etiology of all of the above findings appears to be a mutation in a tumor suppressor gene that also plays a role in normal embryonic development.

Genetic influences in women's oral health.

Variations in the genetic code have been described in an ever increasing array of conditions. This article focuses on a select group of disorders chosen for their relevance both to women and the dental practitioners who care for them. Many of these disorders also illustrate important advances in understanding the complex interaction between an individual's genetic code make-up and the surrounding environment.

[Cowden disease: report of 8 cases in 2 families (author's transl)]. / Maladie de Cowden: a propos de 8 cas familiaux.

These 8 cases of multiple hamartoma syndrome are the first reported in Switzerland. Two men aged respectively of 65 and 28 years presented a cobblestone appearance of the gingiva and of the tongue ("pebbly tongue"), which suggested Cowden disease. This diagnosis was confirmed by the discovery of numberous skin lesions, a thyroid goiter, gastrointestinal polyposis, and a mild skelettal dysmorphosis. The older patient had a grade one carcinoma of the bladder; his son and his daughter presented the syndrome, which was also discovered in the family of the second patient (his father, his brother, his sister and one of her daughters). The ultrastructural study of two skin biopsies demonstrated anomalies of the fibroblasts and collagen fibers.

A missense mutation accelerating the gating of the lysosomal Cl-/H+-exchanger ClC-7/Ostm1 causes osteopetrosis with gingival hamartomas in cattle.

Chloride-proton exchange by the lysosomal anion transporter ClC-7/Ostm1 is of pivotal importance for the physiology of lysosomes and bone resorption. Mice lacking either ClC-7 or Ostm1 develop a lysosomal storage disease and mutations in either protein have been found to underlie osteopetrosis in mice and humans. Some human disease-causing CLCN7 mutations accelerate the usually slow voltage-dependent gating of ClC-7/Ostm1. However, it has remained unclear whether the fastened kinetics is indeed causative for the disease. Here we identified and characterized a new deleterious ClC-7 mutation in Belgian Blue cattle with a severe symptomatology including perinatal lethality and in most cases gingival hamartomas. By autozygosity mapping and genome-wide sequencing we found a handful of candidate variants, including a cluster of three private SNPs causing the substitution of a conserved tyrosine in the CBS2 domain of ClC-7 by glutamine. The case for ClC-7 was strengthened by subsequent examination of affected calves that revealed severe osteopetrosis. The Y750Q mutation largely preserved the lysosomal localization and assembly of ClC-7/Ostm1, but drastically accelerated its activation by membrane depolarization. These data provide first evidence that accelerated ClC-7/Ostm1 gating per se is deleterious, highlighting a physiological importance of the slow voltage-activation of ClC-7/Ostm1 in lysosomal function and bone resorption.

Variability in the Michelin tire syndrome. A child with multiple anomalies, smooth muscle hamartoma, and familial paracentric inversion of chromosome 7q.

We describe a 2 1/2-year-old boy who has hirsutism and ringed creases of the extremities associated with an underlying smooth muscle hamartoma. Cutaneous findings in this child resemble those in other reports of the "Michelin tire syndrome." Histologic examination showed numerous well-demarcated fascicles of smooth muscle cells randomly distributed at all levels of the reticular dermis with haphazard orientation. These cells were immunoreactive with desmin, which confirmed their smooth muscle nature. In addition to the skin changes, this child has multiple unusual phenotypic anomalies, some of which have not previously been associated with the Michelin tire syndrome. These include distinctive facial dysmorphia, submucous cleft palate, lateral clefting of the mouth, genital, and dental anomalies. He also developed seizures at age 2 1/2 years and has moderate developmental delay. The patient and his mother have apparently identical paracentric inversions of the long arm of chromosome 7 (46,XY,inv(7)(q22q31.3) with no detectable loss or gain of either chromosomal material or DNA markers from the cystic fibrosis (CFTR) region. The relevance, if any, of the karyotypic abnormality to the phenotype in this child is discussed.

Multiple hamartoma and neoplasia syndrome (Cowden's syndrome).

A case report involving a patient with Cowden's syndrome is presented. The patient's family is shown to be affected in a pattern consistent with an autosomal dominant form of transmission of this inherited disorder. The disorder can be diagnosed in its early stages by gingival and cutaneous manifestations; it is emphasized that the dentist is therefore perhaps the best-qualified health care professional to recognize the disease in its early stages and to alert the patient to be monitored for later predictable neoplasia which can perhaps be treated before metastasis develops.

Disseminated hereditary gastrointestinal polyposis with orocutaneous hamartomatosis (Cowden's disease).

Cowden's disease, first described by Lloyd and Dennis in 1962, is a rare disseminated polyposis of the gastrointestinal tract with an autosomal dominant inheritance pattern, infrequently cited in the contemporary gastroenterological literature. In addition to multiple polyps, which are scattered throughout the gastrointestinal tract from the mouth to the anus, orocutaneous hamartomas and frequent benign and malignant cutaneous, thyroid and breast tumors are thought to represent the most common manifestations of the disease. Ectodermal lesions are most frequently reported as a salient feature, and represent the most consistent element in the definition of this condition in the majority of cases, most of which are recorded in the dermatological literature (multiple hamartoma syndrome or Cowden's disease). This article presents four cases of Cowden's disease, the patients being members of two genetically unrelated families. All four patients had disseminated polyposis of the gastrointestinal tract, extending from the oral mucosa to the anus, while the cutaneous lesions and the concomitant tumors were present either in a fully developed or only rudimentary form, or were even absent. The authors propose that the term "disseminated hereditary gastrointestinal polyposis with orocutaneous hamartomatosis " be introduced and consistently used in the gastroenterological literature when referring to Cowden's disease, which seems more common than previous reports in the literature would indicate.

[Gorlin-Goltz phakomatosis (author's transl)]. / Phacomatose de Gorlin-Goltz.

Having had the occasion of observing a new case, the authors have started on a new description of a specific autosomal dominant inheritance disease, description which connects an eye trouble with basal cell nevi, with jaw cysts as well as with malformations of the skeleton and nervous lesions, the tumoral lesions having the essential characteristic of possessing and evolutive potential. The authors explain the reasons which have led them to give to this specific disease the name of Gorlin-Goltz phacomatosis.

[Cowden's disease. A report on two cases in Swiss families (author's transl)]. / Maladie de Cowden. Observation de deux familles suisses.

Described by Lloyd and Dennis in 1963, Cowden's disease is a familial affection in which are found associated lesions of the buccopharyngeal mucosa (papillomatosis, papules, scrotal tongue), various types of skin lesions (verruciform keratotic papules, papilloma, lipoma, angioma, etc...), visceral manifestations usually related to lesions in the thyroid, breasts, or digestive tract (hamartoma or malignant tumors), and skeletal dysmorphism. The two patients were from different families, were aged 65 and 28 years, and had presented for consultation because of buccal mucous membrane papillomatosis, and in one case, hemorrhagic gingivitis. Cowden's disease was diagnosed from the clinical examination, past history, and investigations after hospital admission. The main value of the mucosal and cutaneous lesions is their diagnostic significance, enabling a synthesis of the multiple dispersed manifestations to be made, and a possible visceral tumor to be discovered in the early stages.

[Schimmelpenning-Feuerstein-Mims syndrome and its neurologic manifestations. 6 personal cases and review of the literature]. / Das Schimmelpenning-Feuerstein-Mims-Syndrom und seine neurologische Symptomatik. 6 eigene Kasuistiken und Literaturübersicht.

The Schimmelpenning-Feuerstein-Mims-syndrome includes deformities and dysplasias of the skin, eyes, brain, skeleton, and heart. It may result from a malformation of the ectodermal and mesodermal blastoderm in the third week of gestation. We here report on 6 patients who presented between 1977 and 1993 in comparison with those cases in the literature. All children presented neurologic symptoms. The major symptom was a linear epidermal nevus. In addition we found mental retardation, convulsions, asymmetries of the cranial structures or dilated cerebral ventricles ipsilateral to the nevus. One child had a defect of the skull and scalp, a symptom not previously mentioned in the literature. Our patients exhibited a wide phenotypice spectrum ranging from mild to severe forms. Severe neurological symptoms were also found in patients despite minimal dermal involvement.