Mucoepithelial Dysplasia Research Articles

P20 A Rare Case of Hereditary Mucoepithelial Dysplasia With Long Term Follow Up

Abstract This 28-year old woman initially presented at 2 years of age with patchy alopecia, perianal erythema and widespread rough skin. Prior to her first birthday she was diagnosed with bilateral corneal ulceration and was treated initially with soft contact lenses. She had no features of ichthyosis or hyperkeratosis and teeth, nails and eyelashes were normal. The hair loss progressed with involvement of the eyebrows. On examination, there was widespread keratosis pilaris, perianal and vulval erythema and angular cheilitis. Light microscopy of the cut hair was essentially normal. A clinical diagnosis of hereditary mucoepithelial dysplasia was made at that time. She recently underwent genetic testing which has confirmed the diagnosis. She is now registered blind and wears a wig. Her IQ is normal. Hereditary mucoepithelial dysplasia (HMD; OMIM 158310) is a rare autosomal dominant genodermatosis characterised by chronic mucosal lesions associated with keratitis, non-scarring alopecia, keratosis pilaris and psoriasiform perineal intertrigo. A novel causative heterozygous pathogenic variant c.1580G>T (p.Arg527Leu) was identified in our patient in the sterol regulatory element-binding factor 1 (SREBF1) gene. This is involved in promoting the transcription of lipogenes that are associated with epidermal cholesterol and fatty acid biosynthesis. HMD is allelic with autosomal dominant IFAP showing considerable phenotypic overlap and should be considered in patient with congenital hypotrichosis.

Recurrent Vascularizing Keratitis in Infants With Hereditary Mucoepithelial Dysplasia Related to SREBF1 Mutation.

This study aims to present ophthalmic manifestations of 2 infants with hereditary mucoepithelial dysplasia (HMD) related to SREBF1 mutation over a 5-year period. Two female infants with an unremarkable perinatal history were evaluated for photophobia that had been manifest since 3 months after birth and diffuse scalp alopecia. Complete ocular examinations under anesthesia were performed, as well as genetic and systemic workup. Both patients had vascularizing keratitis in both eyes, characterized by the growth of corneal new vessels from the 360 degrees periphery to the center and the formation of stromal leucomatous opacity at the leading edge. The keratitis partially regressed in response to topical corticosteroids and waxed and waned during the 5 years of follow-up. In addition, the loss of scalp hair developed in a cyclical pattern, causing diffuse scalp alopecia in the patients. Rheumatologic, nutritional, and developmental evaluations were within normal ranges. Whole-exome sequencing identified a heterozygous c.1669C>T (p.Arg557Cys) pathogenic variant in the SREBF1 gene associated with HMD in both patients. In pediatric patients with recurrent vascularizing keratitis and diffuse scalp alopecia starting early in life, HMD should be considered, and genetic tests and collaboration with dermatologists and pediatricians on the diagnosis should be provided.

Ichthyosis follicularis, atrichia and photophobia (IFAP) and hereditary mucoepithelial dysplasia: Two syndromes that share a common clinical spectrum.

Ichthyosis follicularis, atrichia and photophobia syndrome (IFAP) is an X-linked inherited disease caused by pathogenic variants in the gene encoding the membrane-bound transcription factor peptidase, site 2 (MBTPS2). Clinical presentation includes ichthyosis follicularis, alopecia, photophobia and developmental delay. Hereditary mucoepithelial dysplasia (HMD) is a dominantly inherited disease characterized by keratitis, non-scarring alopecia, skin lesions including follicular keratosis, perineal erythema, and mucosal involvement. Recently, variants in SREBF1, a gene coding for a transcription factor related to cholesterol and fatty acid synthesis, have been associated with the disease. These two syndromes share a common clinical spectrum. Here, we describe an IFAP syndrome patient with a novel variant in the MBTPS2 gene and an HMD patient with a previously reported variant in the SREBF1 gene. In addition, we present a review of the literature describing the triad characterized by non-scarring alopecia, keratosis follicularis, and ocular symptoms common in both IFAP and HMD patients to raise awareness of these underdiagnosed diseases. We also highlight the subtle differences in clinical presentation between the two disorders to better enable differentiation.

Hereditary Mucoepithelial Dysplasia and Autosomal-Dominant IFAP Syndrome Is a Clinical Spectrum Due to SREBF1 Variants

We read with great interest the recent report by Morice-Picard et al. (2020) on how mutations in SREBF1 (Online Mendelian Inheritance in Man: 184756) are associated with hereditary mucoepithelial dysplasia (HMD) (Online Mendelian Inheritance in Man: 158310). SREBF1 encodes SREBP1, which is involved in promoting the transcription of lipogenes that are associated with cholesterol and fatty acid biosynthesis (Zhang et al., 2017).

Exome sequencing identifies a SREBF1 recurrent ARG557CYS mutation as the cause of hereditary mucoepithelial dysplasia in a family with high clinical variability

Hereditary mucoepithelial dysplasia (HMD) is an uncommon autosomal dominant disease affecting skin, mucosae, hair, eyes, and lungs. Prominent clinical features include non-scarring alopecia, mucosal erythema, perineal erythematous intertrigo, and involvement of the conjunctival mucosa. To date, 20 familial or sporadic HMD cases have been described, most of them originating from Caucasian ethnic groups. In this study, a novel HMD pedigree, including an affected father and his daughter, is reported. Clinical expression showed significant differences in affected subjects, especially in the distribution and severity of skin lesions. Exome sequencing demonstrated that both affected subjects carried a heterozygous c.1669C>T (p.Arg557Cys) pathogenic variant in the SREBF1 gene. Our results improve the knowledge of the clinical and genetic features of HMD. In addition, a comparative review of the clinical features of all published HMD cases is presented.

Palatal Erythema with Histological Psoriasiform Pattern: An Enigmatic Oral Finding Shared by a Range of Conditions.

Long standing, asymptomatic, well-demarcated erythema of the hard palate with a histopathological psoriasiform pattern comprises a challenging diagnosis. We present a series of patients with such clinical and histological findingsand discuss the possible diagnoses. We collected all patients with palatal erythematous lesions that had well-documented clinical examination. Excluded were patients with definitive diagnosis of oral infections (e.g. candidiasis), neoplastic/pre-neoplastic lesions, auto-immune diseases, reactive lesions, blood disorders and vascular malformations. Thirteen patients (six females, seven males, age range 11-56years) were included. Histopathologically, a psoriasiform pattern was observed in all biopsied lesions. One patient was diagnosed with hereditary mucoepithelial dysplasia (HMD) and four with cutaneous psoriasis. The remaining eight patients were otherwise healthy. A combination of persistent, asymptomatic palatal erythematous lesion with psoriasis-like histopathology may represent an oral manifestation of HMD or psoriasis, concomitant to extra-oral features. In lack of any known medical background, the term "oral psoriasiform mucositis" is suggested.

Hereditary Mucoepithelial Dysplasia Results from Heterozygous Variants at p.Arg557 Mutational Hotspot in SREBF1, Encoding a Transcription Factor Involved in Cholesterol Homeostasis

Hereditary Mucoepithelial Dysplasia Results from Heterozygous Variants at p.Arg557 Mutational Hotspot in SREBF1, Encoding a Transcription Factor Involved in Cholesterol Homeostasis

Hereditary mucoepithelial dysplasia: unique histopathological findings in skin lesions

Hereditary mucoepithelial dysplasia (HMD) is a rare, autosomal dominantly inherited, multisystem disease thought to be caused by abnormalities in desmosomes and gap junctions. HMD affects the skin, mucosae, hair, eyes and lungs. Nearly all patients clinically display the triad of non-scarring alopecia, well-demarcated mucosal erythema and erythematous intertriginous plaques. Although histopathological findings of mucous membrane epithelium have been well characterized, only three reports have described histopathologic findings in the skin. We report a case with unique histopathological findings not previously reported in HMD.

Hereditary Mucoepithelial Dysplasia: Report of Two Sporadic Cases

Hereditary mucoepithelial dysplasia (HMD) is a rare genodermatosis characterized by nonscarring alopecia, fiery red gums, perineal erythema, and visual impairment. Histologically, dyskeratotic keratinocytes and a small number of desmosomes are the hallmark of the disease. We report on two unrelated patients who presented with typical clinical and histologic features of HMD along with other unreported clinical findings.

Long-Term Ocular Follow-up in a Case With Hereditary Mucoepithelial Dysplasia

Hereditary mucoepithelial dysplasia is a rare desmosomal gap junction abnormality known to produce keratitis and cataracts in addition to multiple systemic problems. It generally carries a poor visual prognosis due to corneal scarring, amblyopia, and side effects of the treatment. The authors present a sporadic case of hereditary mucoepithelial dysplasia with an unusually good visual outcome and suggest that timely and appropriate intervention can improve the visual prognosis of this rare disorder.

Abnormal Cervical Smear in Hereditary Mucoepithelial Dysplasia

Hereditary mucoepithelial dysplasia is a disorder that involves the mucosa, skin, hair, eyes, and lungs. It is an autosomal dominant condition, although sporadic cases have been reported. The syndrome is caused by an abnormality in desmosomes and gap junctions. We report a case of abnormal cervical smear in an affected individual. Vaginal, oral, and urinary cytological smears show a lack of epithelial cell maturation, large paranuclear cytoplasmic vacuoles, and cytoplasmic strand-shaped inclusions. Abnormal Pap cervical tests have been reported in affected individuals. It has been found that a misinterpretation of abnormal from a cervical smear may lead to an unnecessary hysterectomy. We believe this disorder should be brought to the attention of colposcopists because misinterpreted abnormal cervical Pap tests can lead to unnecessary treatment in such affected individuals.

Blepharophimosis, corneal vascularization, deafness, and acroosteolysis: A “new” syndrome?

We report on a patient with blepharophimosis who after unsuccessful surgery developed progressive corneal vascularization. The patient had conductive hearing loss, acroosteolysis of the phalanges, arthropathy, loss of subcutaneous fat of the hands, feet and face, and oligospermia. He had had spontaneous pneumothorax four times. We have found no similar case reports in the literature and suggest that this is a new syndrome, which must be differentiated from hereditary mucoepithelial dysplasia, mandibuloacral dysplasia, keratitis-ichthyosis-deafness syndrome, Hajdu-Cheney syndrome, Penttinen syndrome, and mucopolysaccharidoses.

Hereditary mucoepithelial dysplasia: clinical, ultrastructural and genetic study of eight patients and literature review

Hereditary mucoepithelial dysplasia is a dominantly inherited disease, mainly characterized by chronic mucosal lesions associated with keratitis, non-scarring alopecia, keratosis pilaris and perineal intertrigo. Since the original report by Witkop, this condition has been considered to be a disorder of desmosome/gap junction formation, but there has been no ex vivo investigation of these components using genetic and immunolabelling techniques. To perform light and immunoelectron microscopic studies, and partial genetic analysis on five patients in a family and three sporadic cases and to point out similarities of this rare disorder with chronic mucocutaneous candidiasis and other follicular keratosis syndromes, i.e. ichthyosis follicularis-alopecia-photophobia (IFAP), keratitis-ichthyosis-deafness (KID) and Siemens syndromes. Biopsies from the involved oral mucosa and armpit skin of patient 1 were prepared for standard histopathology, electron microscopy and immunocytochemistry. Microsatellite genotyping was performed in three affected family members. Direct sequencing after polymerase chain reaction amplification of the entire coding region was performed. A 14-year-old male had recurrent keratitis, widespread keratosis pilaris, perineal intertrigo, hypotrichosis and oral mucosal involvement. A similar phenotype was noted in four members of his family and in three sporadic cases. Histological examination of oral mucosa and skin samples showed a psoriasiform pattern, dyskeratotic features and cytoplasmic vacuoles. Expression of connexins (Cx), desmosomal, adherens junction and cytoskeleton proteins (Cx 26, 32 and 43, desmogleins 1 and 2, plakoglobin, desmoplakins I-II, plakophilin 1, beta-catenin, E-cadherin, keratins, beta-tubulin, vimentin and actin) was normal. Ultrastructural studies showed a reduced number of desmosomes. Dyskeratotic cells exhibited internalized gap junctions, long filamentous inclusions reactive with antikeratin antibodies, and bundles of perinuclear fibres resembling clear tonofilaments. Genetic analysis in the studied family excluded the desmosomal cadherins in chromosome 18q12 as candidate genes. A diagnosis of hereditary mucoepithelial dysplasia should be strongly suggested by the triad of non-scarring alopecia, well-demarcated erythema of oral mucosa and psoriasiform perineal rash, after exclusion of the clinically related follicular keratosis syndromes. Defective expression of cytoskeleton elements and/or a modification of mechanisms regulating junction-cytoskeleton assembly may be primarily responsible for impaired epithelial cohesion.

Hereditary Mucoepithelial Dysplasia

We report an individual with the rare autosomal recessive condition known as hereditary mucoepithelial dysplasia. The diagnosis was based on clinical features and characteristic ultrastructural changes in oral mucosal biopsy specimens.

New clinical aspects of hereditary mucoepithelial dysplasia

Hereditary mucoepithelial dysplasia (HMD) is a multiepithelial disorder. It is transmitted as an autosomal dominant trait (McKusick: Mendelian Inheritance in Man-Catalogs of Autosomal Dominant, Autosomal Recessive, and X-Linked Phenotypes, 8th edition. Baltimore: The Johns Hopkins University Press, pp 499, 1988). HMD is characterized by variable combinations of lesions of skin, hair, orificial mucosa, gingiva, eyes, and lungs. In some previously described patients, the corneal and pulmonary lesions were progressive and led to blindness, recurrent pneumonia, and/or premature death. On light microscopy, the lesion is characterized by dyskeratosis, and, on electron microscopy, by a paucity of gap junctions and desmosomes. Here, we describe a new 5-generation kindred in which affected individuals had the same histologic characteristics but a somewhat different clinical spectrum and a more benign course. HMD should be considered in the differential diagnosis of childhood alopecia, follicular hyperkeratosis, keratoconjunctivitis, juvenile cataracts, gingival hyperemia, restrictive lung disease, and esophageal stenosis or webs.

Clinical, histologic, cytologic, and ultrastructural characteristics of the oral lesions from hereditary mucoepithelial dysplasia: A disease of gap junction and desmosome formation

Hereditary mucoepithelial dysplasia is an autosomal, dominantly inherited disorder affecting all of the orificial mucosa with cataracts, follicular keratosis of skin, nonscarring alopecia, bouts of pneumonia, spontaneous pneumothorax, and terminal cor pulmonale. 1 The oral lesion is a fiery red, flat or micropapillary-appearing mucosa most frequently involving the gingiva and hard palate. All oral and pharyngeal mucosa may be involved, however. Red scrotal mucosa of the tongue is common. Histologically, the oral mucosa shows a lack of cornified and keratinized cells, a decrease in the thickness of the epithelial cell layer, dyshesion, and dyskeratosis. Papanicolaou smears show lack of epithelial cell maturation, poikilocytosis, anisocytosis, large paranuclear cytoplasmic vacuoles, and cytoplasmic strand-shaped inclusions. Ultrastructural features include a paucity of desmosomes, intercellular accumulations of amorphous material, cytoplasmic vacuoles, and paranuclear lesions with strands of material resembling gap junctions and desmosomes. The condition most likely represents a basic defect in gap junction and desmosome formation.