Clinical and molecular characterization of lipoid proteinosis in Namaqualand, South Africa

Cutaneous findings and treatment responses of lipoid proteinosis patients

OBJECTIVES

Lipoid proteinosis (LP) is a rare autosomal recessive disorder characterized by the accumulation of hyaline-like material in the skin, oral mucosa, larynx, and brain. This study aimed to evaluate the dermatological findings and treatment responses of patients diagnosed with LP.

METHODS

This retrospective study included 41 patients diagnosed with LP at our clinic between May 2018 and January 2023. The diagnosis of LP was established in 22 patients by detecting mutations in the ECM1 gene. In comparison, in 19 patients, it was based on typical clinical findings and histopathological examination of lesioned skin. Clinical and demographic data such as dermatological findings, treatments received, and responses to treatment were recorded from patient files.

RESULTS

All patients exhibited skin thickening and acneiform scars. The most commonly observed additional dermatological findings were moniliform blepharosis (60.9%), varioliform scars (29.2%), waxy papules and plaques (24.3%), and blisters with crusts (19.5%). Verrucous lesions, diffuse yellow plaques, and scarring alopecia were observed in adult patients, while hypopigmented lesions and blisters with crusts were seen in the pediatric age group. The most frequently used treatments were acitretin (14.6%) and systemic steroids (9.7%). No improvement in skin lesions was observed in patients treated with acitretin, whereas complete resolution of blisters with crusts was noted in patients treated with systemic steroids.

CONCLUSIONS

In addition to the existing literature on dermatological manifestations of LP, hypopigmented lesions and atrophoderma vermiculatum-like lesions can also be observed in these patients. We believe that short-term systemic steroid therapy for vesiculobullous lesions can be considered for treatment. We think prospective studies with more patients and requiring long-term follow-up are needed regarding the effectiveness of acitretin treatment.

A founder deletion in ECM1 of 1163 bp causes lipoid proteinosis in the southeast region of Turkiye

Lipoid proteinosis (LP) is an inherited disorder characterized by the accumulation of hyaline-like material in the skin, oral cavity, and larynx. The primary symptoms include hoarseness, restricted tongue movements, and various skin lesions. LP is caused by biallelic pathogenic variants in the ECM1 gene. We studied 20 patients from nine different families with LP, 19 of whom are from Şanlıurfa in the southeastern region of Turkiye. Overall, the clinical features of the patient cohort were consistent with those mentioned in the literature, except for one exhibited an atrophoderma vermiculatum-like lesion, which is atypical for LP. The clinical exome sequencing analysis revealed three different homozygous variants in the ECM1 gene (NM_004425). While c.1246C>T p.(Arg416*) on Exon 8 and c.806G>A p.(Cys269Tyr) on Exon 7 were detected in 1 patient each, an intragenic deletion of 1163 base-pairs including Exons 9 and 10 (c.1304 + 33_*300del) was identified in 18 patients from 7 unrelated families. The haplotype analysis of the deletion variant indicated a founder effect in the families from the Şanlıurfa province of Turkiye. Based on all this information, copy number variation analysis is recommended for patients with LP. In addition to this rare observation, this study represents the largest examination of the molecular spectrum of LP patients in Turkiye, alongside the clinical spectrum.

Laryngeal features in Lipoid proteinosis: a systematic review and meta-analysis of individual participant data

PURPOSE

Lipoid proteinosis (LP) or Urbach-Wiethe disease (OMIM 247100) is a rare syndrome characterised by early vocal folds infiltration and subsequent multi-organ involvement. LP is often unrecognised and its associated hoarseness is overlooked. The main objective of the study was to investigate hoarseness in LP and implement a diagnosis among otolaryngologists.

METHODS

PubMed/MEDLINE and OMIM databases were systematically searched. Authors concentrated the search on published articles starting from the discovery of the pathogenesis of LP by Hamada et al. in 2002. Only cases in which a diagnosis was reported both clinically and through biopsy and/or genetic molecular testing were included. Characteristics of the LP cases were extracted from each included study. Results were obtained through Generalized Estimating Equations.

RESULTS

The search strategy yielded 217 articles, of which 74 (34.1%) met the selection criteria. A total of 154 cases were included. Hoarseness was described in all LP cases and clearly stated as the onset symptom in 68.8%. The onset was on average at 19 months of age (CI: 3.00-20.00), while the mean age at diagnosis was 15 years (CI: 10.00-30.00). Therefore, the diagnostic delay amounted to 13.42 years (CI: 8.00-23.83). Hoarseness alone was responsible for an LP diagnosis in only 14.3% of cases. In 43.5% of cases, genetic analysis of the ECM1 gene was performed and exon 6 was the most frequently altered portion.

CONCLUSION

Analysing the largest number of published cases, the study underlined that hoarseness is the key symptom for diagnosing LP since early childhood, though frequently overlooked.

Identification of a Novel Mutation of Extracellular Matrix Protein 1 Gene in a Chinese Family with Lipoid Proteinosis

Lipoid proteinosis (LP) is a rare autosomal recessive disorder caused by mutations in extracellular matrix protein 1 (ECM1), a glycoprotein expressed in skin. Whole-exome sequencing (WES) was used to investigate two Chinese siblings with suggestive clinical features of LP. They shared one known (c.960G>A) and one novel (c.1081G>T) pathogenic variant in ECM1 gene, inherited from their unaffected parents. The novel mutation (c.1081G>T) led to a termination codon at position 361 and caused nonsense-mediated mRNA decay and lost the function. Our finding expands the genetic etiology spectrum of LP.

Late presentation of laryngeal lipoid proteinosis: a case report and review of the literature

Lipoid proteinosis (LP) is a rare autosomal-recessive disease characterized by the deposition of hyaline material infiltrating multiple body organs, including the larynx. The possible clinical presentations are wide-ranging. Laryngeal involvement results in dysphonia that is noted at birth or infantile years. The diagnosis is based on histological findings, and the management options vary depending on the severity of the symptoms. In this paper, we report an unusual case of LP with laryngeal involvement in an adult patient, along with a review of current literature.

Human Metabolites of Hamaforton™ (Hamamelis virginiana L. Extract) Modulates Fibroblast Extracellular Matrix Components in Response to UV-A Irradiation

Hamamelis virginiana L. a rich source of both condensed and hydrolyzable tannins, utilized to treat dermatological disorders. Since no experimental and clinical data is available for its use as oral formulation in skin related disorders, the purpose of this study was to investigate the effects of Hamaforton™ (Hamamelis virginiana extract) metabolites on gene dysregulation induced by ultraviolet A radiation in cultured human dermal fibroblasts. A combination of in vivo and ex vivo experimental designs has been exploited in order to take into account the polyphenol metabolic transformation that occurs in humans. 12 healthy volunteers received either a capsule of Hamaforton™ or a placebo in a randomized, blinded crossover trial. After Hamaforton™ ingestion, the kinetic of appearance of galloyl derivatives was measured in plasma. Then, in the ex vivo experiment, the serum isolated after supplementation was used as a source of Hamaforton™ metabolites to enrich the culture medium of dermal fibroblasts exposed to ultraviolet A radiation. Three different gallic acid metabolites (4-O-methyl gallic acid, 4-O-methyl gallic acid sulphate and trimethyl gallic acid glucuronide) were identified in volunteer plasma. While, ultraviolet A irradiation of dermal fibroblasts affected the expression of extracellular matrix genes, the presence of Hamaforton™ metabolites in the culture media did not affect the expression of most of those genes. However, the activation of the expression of 10 different genes involved in repair processes for the maintenance of skin integrity, suggest that the metabolites can play a role in damage recovery. To our knowledge, this is the first study that demonstrates the bioavailability of Hamaforton™ phenolic compounds, and the effects of its metabolites on cultured dermal fibroblast response to ultraviolet A irradiation.

Are the kidneys involved in lipoid proteinosis? Study of 22 patients

AIM

Lipoid proteinosis (LP) is a systemic, progressive, rare genodermatosis that manifests in early life with mucocutaneous lesions. Kidney involvement has not been described before, hence we aimed to investigate kidney findings in LP patients.

MATERIALS AND METHODS

In this cross-sectional study, LP patients who were followed up and diagnosed with clinical, histopathological and radiological findings in the Dermatology outpatient clinic were invited to the Pediatric Nephrology Clinic. Biochemical, spot urine and 24-hour urine collection tests and ultrasound scans were scanned for the functional and anatomical status of the kidneys. Healthy controls who visited the Pediatric Nephrology Clinic during study periods for other reasons were invited to participate as the control group.

RESULTS

Data of 44 participants (22 LP patients, mean age 14.5 years and 22 healthy controls, mean age 14.3 years) were available for the analysis. Ultrasound scans revealed simple renal cysts in 68% of LP patients. The cysts were bilateral in 4 patients, while no cyst was detected in healthy controls. Biochemical parameters, proteinuria, and albuminuria were all within the normal reference range in both LP patients and healthy controls, whereas LP patients had statistically significant lower serum albumin and higher C-reactive protein levels than healthy controls.

CONCLUSION

Multiple simple renal cysts were detected in the majority of LP patients, and this finding could be part of the systemic involvement of the disease. Renal functions and biochemical parameters were within the normal reference range, but low serum albumin and high C-reactive protein levels in LP patients may be the signs of elevated systemic inflammation. Although more studies are needed to better define these findings, the presence of many simple renal cysts in LP patients was found to be the most important finding of this study.

Roles of the bed nucleus of the stria terminalis and amygdala in fear reactions

The bed nucleus of the stria terminalis (BNST) plays a critical modulatory role in driving fear responses. Part of the so-called extended amygdala, this region shares many functions and connections with the substantially more investigated amygdala proper. In this chapter, we review contributions of the BNST and amygdala to subjective, behavioral, and physiological aspects of fear. Despite the fact that both regions are together involved in each of these aspects of fear, they appear complimentary in their contributions. Specifically, the basolateral amygdala (BLA), through its connections to sensory and orbitofrontal regions, is ideally poised for fast learning and controlling fear reactions in a variety of situations. The central amygdala (CeA) relies on BLA input and is particularly important for adjusting physiological and behavioral responses under acute threat. In contrast, the BNST may profit from more extensive striatal and dorsomedial prefrontal connections to drive anticipatory responses under more ambiguous conditions that allow more time for planning. Thus current evidence suggests that the BNST is ideally suited to play a critical role responding to distant or ambiguous threats and could thereby facilitate goal-directed defensive action.

Evaluation of cochlear involvement and hearing function in lipoid proteinosis patients

BACKGROUND

Lipoid proteinosis (LP) is a rare genodermatosis involving amorphous hyaline accumulation in the skin, oral mucosa, larynx, mucous membranes, and viscera.

AIMS

In this study, we aimed to investigate the effects of hyaline accumulation on cochlear function and hearing in LP patients.

PATIENTS/METHODS

In this prospective study, 20 patients who were followed up with a diagnosis of LP between October 2016 and April 2020 in our clinic and 20 healthy individuals of the same age and gender, as a control group, were included. Pure-tone audiometry, tympanometry, and distortion-product otoacoustic emission tests of the patient and control groups were performed. The audiological results of the LP and control groups were compared statistically.

RESULTS

In the comparison of air-conduction thresholds between groups in pure-tone audiometry, hearing thresholds in the patient group were found to be higher than the control group at frequencies of 250, 4000, 6000, and 8000 Hz for the right ear, and 500 and 4000 Hz for the left ear. In the comparison of signal-noise responses between groups in distortion-product otoacoustic emission (DP-OAE) test, signal-noise responses in the right and left ear at frequencies of 1000, 2000, 4000, and 6000 Hz were lower in the patient group than in the control group.

CONCLUSION

We found that the cochlear functions of patients with LP were affected due to the increase in hearing thresholds and decreased signal-noise responses. We think that LP patients are candidates for hearing loss in their later life.

Lipoid Proteinosis: A Rare Disease In Pediatric Dentistry

This report describes the diagnostic process of a rare disorder in a Brazilian female child. The patient presented initially as a 7-year-old with multiple whitish submucosal nodules of a fibrous consistency in the lower lip, but with an inconclusive pathology report. When she turned 9 years of age, she presented with exacerbation of the original clinical findings, which then involved the upper lip, buccal mucosa, tongue and lingual frenulum. In addition, dermatological lesions were noted on the child's limbs and face, as well as a hoarse voice. Histopathological examination of the buccal mucosa revealed dense connective tissue with hyaline foci, which were positive with periodic acid-Schiff (PAS) staining and resistant to diastase digestion. Clinical and histopathological findings led to the diagnosis of a rare genetic disease with fewer than 300 reported cases - lipoid proteinosis. Magnetic resonance imaging revealed calcium deposits in her amygdaloid region of the brain, and nasopharyngolaryngoscopy revealed lesions in her vocal cords. The patient currently is stable and under multidisciplinary follow-up, but no treatment has been recommended to date.

A novel nonsense mutation in exon 9 in the extracellular matrix protein 1 gene associated with lipoid proteinosis: A case report

Lipoid proteinosis is a rare autosomal recessive genodermatosis that is caused by loss-of-function mutations in the extracellular matrix protein 1 gene. This study identifies a novel nonsense mutation in exon 9 of the extracellular matrix protein 1 gene associated with lipoid proteinosis, contributing to recent advances in our understanding of the molecular genetics underlying this disease. It is important to identify the mutations in the extracellular matrix protein 1 gene that are associated with lipoid proteinosis and how these affect protein function. Understanding the molecular basis for such genetic disorders may lead to novel therapeutic approaches for treating hereditary genodermatoses.

The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

Rodent research delineates how the basolateral amygdala (BLA) and central amygdala (CeA) control defensive behaviors, but translation of these findings to humans is needed. Here, we compare humans with natural-selective bilateral BLA lesions to rats with a chemogenetically silenced BLA. We find, across species, an essential role for the BLA in the selection of active escape over passive freezing during exposure to imminent yet escapable threat (Timm). In response to Timm, BLA-damaged humans showed increased startle potentiation and BLA-silenced rats demonstrated increased startle potentiation, freezing, and reduced escape behavior as compared to controls. Neuroimaging in humans suggested that the BLA reduces passive defensive responses by inhibiting the brainstem via the CeA. Indeed, Timm conditioning potentiated BLA projections onto an inhibitory CeA pathway, and pharmacological activation of this pathway rescued deficient Timm responses in BLA-silenced rats. Our data reveal how the BLA, via the CeA, adaptively regulates escape behavior from imminent threat and that this mechanism is evolutionary conserved across rodents and humans.

Common and Founder Mutations for Monogenic Traits in Sub-Saharan African Populations

This review highlights molecular genetic studies of monogenic traits where common pathogenic mutations occur in black families from sub-Saharan Africa. Examples of founder mutations have been identified for oculocutaneous albinism, cystic fibrosis, Fanconi anemia, and Gaucher disease. Although there are few studies from Africa, some of the mutations traverse populations across the continent, and they are almost all different from the common mutations observed in non-African populations. Myotonic dystrophy is curiously absent among Africans, and nonsyndromic deafness does not arise from mutations in GJB2 and GJB7. Locus heterogeneity is present for Huntington disease, with two common triplet expansion loci in Africa, HTT and JPH3. These findings have important clinical consequences for diagnosis, treatment, and genetic counseling in affected families. We currently have just a glimpse of the molecular etiology of monogenic diseases in sub-Saharan Africa, a proverbial “ears of the hippo” situation.

Esophageal Aperistalsis in a Patient with Lipoid Proteinosis

Lipoid proteinosis is a rare disorder with autosomal recessive inheritance, characterized by progressive deposition of hyaline material in the skin, mucous membrane, and different organs of the body, resulting in a multitude of clinical manifestations. A 34-year-old woman presented with hoarseness, dysphagia, eyelid beeding, and acneiform scars on the facial skin and extremities. The patient was diagnosed clinically as having lipoid proteinosis, which was confirmed by laryngeal biopsy. The objective of the present report is to describe this rare entity. This case report also illustrates that lipoid proteinosis may show protean clinical features and yet may remain undiagnosed for many years.

Lipoid proteinosis: A clinical and molecular study in Egyptian patients

Lipoid proteinosis (LP) is an autosomal recessive disorder caused by the loss of function of ECM1 gene. Clinical features include varying degrees of skin thickening, hoarseness of voice and less frequently neuropsychiatric abnormalities. Twelve patients from ten unrelated families with a clinical diagnosis of lipoid proteinosis were enrolled in this study. Extraction of DNA samples of the 12 patients and their parents from peripheral blood by standard methods was performed. Polymerase chain reaction (PCR) amplification of the ECM1 gene was conducted using eight pairs of primers spanning over the 10 exons and splice junctions. Patients exhibited a variety of clinical manifestations with skin affection and hoarseness of voice being the consistent feature. We identified five novel homozygous insertion, small deletion, missense, and splice site mutations as well as two homozygous previously published splice site mutation c.70+1G>C in intron 1 and c.1305-2A>G in intron 8. The specific mutations were: c.10_11insC in exon 1, c.690_691delAG in exon 6, c.734G>A in exon 7, c.1286_1287delAA in exon 8 and c.1393-1G>T in intron 9. The novel mutations c.1393-1G>T and c.10_11insC occurred in three (30%) and two (20%) unrelated patients of the studied families, respectively. Further studies may designate an increased frequency of these mutations among Egyptian LP patients. Identification of pathogenic ECM1 mutations is important for accurate diagnosis and proper genetic counseling.

Extracellular matrix protein 1 gene (ECM1) mutations in nine Iranian families with lipoid proteinosis

Background & objectives:

Lipoid proteinosis (LP) is an autosomal recessive disease. Clinical characteristics of this disease are hoarse voice, scarring of the skin, brain calcifications, and eyelid papules (moniliform blepharosis). Mutations in the ECM1 gene on 1q21.2 are responsible for this disease. This study was conducted to investigate the mutation spectrum of ECM1 gene in nine Iranian families having at least one LP patient diagnosed clinically.

Methods:

The entire ECM1 gene was screened using PCR and direct sequencing in nine Iranian families with 12 suspected LP patients who were referred to the clinic, along with their parents and siblings. Thirty healthy individuals were included as controls.

Results:

In only one patient a homozygous G>A transition at nucleotide c.806 in exon 7 was detected. A G>A substitution at nucleotide 1243 in exon 8 that changes glycine (GGT) to serine (AGT) was observed in most of our patients. Furthermore, in one patient there was a change in the sequence of intron 8, the A>T transition in nucleotide 4307. In addition, in two cases (one patient and one healthy mother with affected child) there was a C (4249) deletion in intron 8.

Interpretation & conclusions:

Our results indicate that although mutation in ECM1gene is responsible for lipoid proteinosis, it is likely that this is not the only gene causing this disease and probably other genes may be involved in the pathogenesis of the LP disease.

A Novel ECM1 Splice Site Mutation in Lipoid Proteinosis: Case Report plus Review of the Literature

Lipoid proteinosis (LP) is an autosomal recessive genodermatosis known to be caused by mutations in ECM1. Nonsense and missense mutations are the most common variations in LP. Up to date, only 6 splice site mutations have been observed. We report on a 26-year-old female LP patient from a Turkish consanguineous family carrying a novel homozygous splice site mutation in intron 8 of the ECM1 gene and summarize the current knowledge on ECM1 mutations and possible genotype-phenotype correlations.

Treatment of lipoid proteinosis with acitretin in two patients from two unrelated Chinese families with novel nonsense mutations of the ECM1 gene

Lipoid proteinosis is a rare recessive genetic disorder caused by loss-of-function mutations to chromosome 1 at 1q21, the extracellular matrix protein 1 (ECM1) gene. Two children with lipoid proteinosis were reported from two unrelated Chinese families, both manifesting with a typical hoarse voice, white acne-like atrophic lesions and scarring on the skin, and beaded papules around the eyelids. The diagnosis had been confirmed by laboratory tests, skin biopsy and laryngoscope examination. Genomic DNA sequencing was performed for both children and their family members. The two children were treated with acitretin for 6 months and followed up for 1 year. Genomic DNA sequencing of the ECM1 gene showed a novel homozygous nonsense mutation of C1522>T (p.R508X) at exon 10 in one patient, and a novel compound heterozygote for a nonsense/frame-shift combination of mutations of R281X/1596delG at exons 7 and 10 in the other patient. The symptom of hoarse voice was improved by 6-month treatment with acitretin, while there was no improvement in the skin lesions. These results demonstrated that acitretin treatment may have efficacy for some of patients with lipoid proteinosis, with superior effect on laryngeal symptoms than skin lesions. However, the conclusive therapeutic effect and underlying mechanisms remain to be further investigated.

Lipoid proteinosis: phenotypic heterogeneity in Iranian families with c.507delT mutation in ECM1

Lipoid proteinosis (LP) is a rare autosomal recessive genodermatosis caused by loss-of-function mutations in the ECM1 gene, and previous studies have noted phenotypic variability. In this study, we examined 12 patients representing three Iranian families for clinical manifestations and genotyped them for mutations in ECM1. LP was diagnosed with characteristic mucocutaneous and neurologic manifestations. Five patients were also subjected to magnetic resonance imaging (MRI)/computed tomography (CT) scan of the central nervous system. DNA was isolated from peripheral blood from patients and their clinically unaffected relatives, and mutations in ECM1 were sought by PCR-based amplification of all exons and flanking intronic sequences, followed by bidirectional Sanger sequencing. Significant phenotypic variability in this multisystem disorder, including presence of convulsions and epilepsy in about half of the patients was noted. In most cases, this was associated with calcifications in the brain detected by MRI/CT scans. Genotyping of the affected individuals in three families from the central region of Iran revealed presence of homozygous c.507delT mutation in ECM1, reflecting the observed consanguinity in these families. This large cohort revealed extensive phenotypic variability in individuals with the same mutation in ECM1. This observation suggests a role for genetic and epigenetic as well as environmental modulation of the phenotype. Identification of mutations allows screening of unaffected individuals for presence or absence of this mutation in extended LP families, with implications for genetic counseling.

Gastrointestinal involvement in lipoid proteinosis: a ten-year follow-up of a brazilian female patient

Lipoid proteinosis is a rare autosomal recessive disease characterized by the deposition of hyaline material in the skin and internal organs. The main clinical features are hoarseness and typical skin lesions. In this report we describe the endoscopic and radiologic findings in a Brazilian female patient presenting extensive gastrointestinal involvement and the evolution of the detected lesions in ten years of follow-up. Initial upper endoscopy and colonoscopy showed a similar pattern of multiple yellowish nodules throughout the esophagus, stomach, duodenum, and colons. Histological analysis confirmed the diagnosis of lipoid proteinosis. In addition, small bowel follow through demonstrated numerous well defined, round, small filling defects throughout the jejunum. Ten years later, the esophageal lesions remained the same, but none of the previous alterations were detected in the stomach, duodenum, and colons. In conclusion, lipoid proteinosis may affect all gastrointestinal organs with the same pattern of macroscopic and microscopic lesions. Some lesions may regress with increasing age.

Treatment of lipoid proteinosis due to the p.C220G mutation in ECM1, a major allele in Chinese patients

Background

Lipoid proteinosis (LP) is known to be resulted from mutations of the extracellular matrix protein 1 gene (ECM1). However, no effective or sustained therapeutic methods to alleviate LP symptoms have been reported.

Methods

Here, we report a 12-year-old boy with LP and recurrent anaphylaxis. The laboratory and histopathological investigations were adopted to confirm the diagnosis, and gene sequencing was performed. We treated this patient with glucocorticoid for three years to relieve the patient’s lipid metabolism disorder and symptoms related to LP and anaphylaxis.

Results

The Laboratory and histopathological investigations showed a lipid metabolism disorder and anaphylaxis in the patient. A homozygous missense mutation p.C220G of ECM1 was identified by Sanger sequencing, which is a major allele in Chinese patients with LP. Notably, after three years’ treatment, the symptoms such as skin lesions, stiff oral mucosa and hoarse voice in the patient were significantly relieved or recovered.

Conclusions

Our report may provide a potentially effective therapeutic approach for the first time to other LP patients who are experiencing recurrent anaphylaxis and/or chronic inflammation.

Two Egyptian cases of lipoid proteinosis successfully treated with acitretin

BACKGROUND

Lipoid proteinosis (Urbach-Wiethe disease) is a rare progressive autosomal recessive disorder, characterized histologically by deposition of periodic acid Schiff-positive, diastase resistant, hyaline-like material into the skin, upper aerodigestive tract, and internal organs.

MAIN OBSERVATION

We report two cases of lipoid proteinosis. A 2-year-old girl presented with vesiculobullous skin lesions on her face, trunk, extremities and scalp, inability to protrude the tongue and hoarseness of voice that appeared few months after birth. The other case is a 4-year-old girl, who presented with waxy papules on face and trunk, hoarseness of voice and enlarged lips and tongue. The lesions healed leaving pitted scars in both cases. Based on clinical, histopathological and laryngoscopy findings, lipoid proteinosis was diagnosed in both cases. Acitretin was started in a dose of 0.5 mg/kg/day in every child. Complete remission of cutaneous lesions and improvement of the hoarseness was observed after one year.

CONCLUSION

Acitretin may be benificial for treatment of mucosal and cutaneous lesions in lipoid proteinosis.

Identification of recurrent c.742G>T nonsense mutation in ECM1 in Pakistani families suffering from lipoid proteinosis

Lipoid proteinosis (LP) is one of the rare, recessive autosomal disorders clinically characterized by widespread deposition of hyaline-like material in the skin, mucosa and viscera. Classical features include beaded eyelid papules, laryngeal infiltration and hoarseness of voice caused by pathogenic mutations in the ECM1 gene located on 1q21.2. In present study ethnically different, three consanguineous Pakistani families with typical cutaneous features of LP were analysed to investigate the underlying molecular basis. PCR based linkage analysis using microsatellite markers localized the families to locus 1q21.2, harboring ECM1 gene. To identify the mutation in the candidate gene (ECM1), Sanger sequencing was carried out. All the families were found to carry c.742 G>T nonsense mutation in exon 7 of the ECM1 gene that resulted in a truncated ECM1 protein containing 247 amino acids instead of 540 (p.E248X). To further investigate the impact and importance of mutation in LP pathogenesis we applied different bioinformatics tools. In silico studies has predicted lack of functional domains and 65 % shorter ECM1 mutant protein. It is the first report of recurrence mutation from Pakistan as c.742G>T nonsense mutation was found in three ethnically different Pakistani families with LP. Study strengthens the conclusion that c.742G>T mutation is the pathological cause of LP. Furthermore, data also support the fact that exon 7 is one of the most common hot spots of pathological mutations in ECM1. The absence of functional domains and truncated sequence most likely contribute to the lack of ECM1 function and thereby influence several aspects of dermal homeostasis that leads to LP pathogenesis.

Acitretin treatment for lipoid proteinosis

Lipoid proteinosis (LP) is a rare, autosomal-recessive disease characterized by the hoarseness and widespread cutaneous scarring, more prominent on sun-exposed areas. Yellow-white plaques can be seen on oral mucosa and on the skin among depressed scars. Histological evaluation of the affected sites shows accumulation of hyaline-like material in dermis and disruption of basement membrane. Although LP is compatible with normal life expectancy, involvement of upper respiratory tract may endanger patient's life, especially in the case of a respiratory tract infection. Involvement of central nervous system has also been reported, but its clinical importance is obscure. Due to the rarity of LP, a definite therapeutical approach is not established. In this paper we describe a 21-year-old LP patient who was treated with acitretin for six months. Although the outcome with cutaneous lesions was not satisfactory, her hoarseness was significantly improved.

A novel missense mutation in exon 7 of the ECM1 gene in an Iranian lipoid proteinosis patient

Lipoid proteinosis (LP) is a rare autosomal recessive disorder. Classical clinical features include warty skin infiltration, papules on the eyelids, skin scarring, as well as extracutaneous abnormalities such as hoarseness of the voice, epilepsy, and neuropsychiatric abnormalities. A defect in the ECM1 gene is responsible for this disease. A 21-year-old female patient from consanguineous parents (first cousins) was referred to our clinic with many symptoms of LP, such as hoarse voice from infancy, diffuse acneiform scars on her face, and hyperkeratosis on her knees and elbows. The entire ECM1 gene was screened using PCR and sequencing. A novel missense mutation was found in exon 7 of this patient. We report a novel missense mutation in exon 7 of the ECM1 gene found in an Iranian LP patient that causes a C269Y amino acid exchange.

Molecular and neurological characterizations of three Saudi families with lipoid proteinosis

Background

Lipoid proteinosis is a rare autosomal recessive disease characterized by cutaneous and mucosal lesions and hoarseness appearing in early childhood. It is caused by homozygous or compound heterozygous mutations in the ECM1 gene. The disease is largely uncharacterized in Arab population and the mutation(s) spectrum in the Arab population is largely unknown. We report the neurologic and neuroradiologic characteristics and ECM1 gene mutations of seven individuals with lipoid proteinosis (LP) from three unrelated consanguineous families.

Methods

Clinical, neurologic, and neuro-ophthalmologic examinations; skin histopathology; brain CT and MRI; and sequencing of the fullECM1 gene.

Results

All seven affected individuals had skin scarring and hoarseness from early childhood. The two children in Family 1 had worse skin involvement and worse hoarseness than affected children of Families 2 and 3. Both children in Family 1 were modestly mentally retarded, and one had typical calcifications of the amygdalae on CT scan. Affected individuals in Families 2 and 3 had no grossneurologic, neurodevelopmental, or neuroimaging abnormalities. Skin histopathology was compatible with LP in all three families. Sequencing the full coding region of ECM1 gene revealed two novel mutationsin Family 1 (c.1300-1301delAA) and Family 2 (p.Cys269Tyr) and in Family 3 a previously described 1163 bp deletion starting 34 bp into intron 8.

Conclusions

These individuals illustrate the neurologic spectrum of LP, including variable mental retardation, personality changes, and mesial temporal calcificationand imply that significant neurologic involvement may be somewhat less common than previously thought. The cause of neurologic abnormalities was not clear from either neuroimaging or from what is known about ECM1 function. The severity of dermatologic abnormalities and hoarseness generally correlated with neurologic abnormalities, with Family 1 being somewhat more affected in all spheres than the other two families. Nevertheless, phenotype-genotype correlation was not obvious, possibly because of difficulty quantifying the neurologic phenotype and because of genetic complexity.

Homozygous frame shift mutation in ECM1 gene in two siblings with lipoid proteinosis

BACKGROUND

The extracellular matrix protein 1 (ECM1) is a glycoprotein, expressed in skin and other tissues. Loss-of-function mutation in ECM1 causes a rare autosomal recessive disorder called lipoid proteinosis. Lipoid proteinosis is presented by varying degrees of skin scars, beaded papules along the eyelid margins, variable signs of hoarseness of voice and respiratory disorders. More than 250 cases of this disorder have been described in the literature, but occurrence of lipoid proteinosis in siblings is very rare. This study was designed to investigate the possible mutation causing lipoid proteinosis in a Pakistani family and to elaborate the scope of possible genetic changes, causing the genodermatosis in Pakistan.

MAIN OBSERVATIONS

In this study, two siblings (12 and 9-years sisters) were presented with scaly itchy lesions on whole body, hoarse voice and macroglossia. Their deceased father had similar clinical manifestations but mother and younger brother were unaffected. Blood samples from clinically affected and unaffected family members were collected with informed consent. The coding region of ECM1 gene containing 10 exons were amplified and sequenced. Both the affected siblings were shown to have homozygous frame shift mutation by deletion of the nucleotide T at 507, codon 169, exon 6. This resulted in a frame shift from codon 169 and appearance of a premature stop codon at 177, causing formation of a mutated protein (176 amino acids) instead of normal ECM1 protein (540 amino acids).

CONCLUSION

A case of homozygous 62-bp insertion in ECM1 gene causing lipoid proteinosis has been reported in another Pakistani family. The current study presents a homozygous frame shift mutation supporting an unusual function of ECM1 protein and broadens the spectrum of disease-linked mutations in this rare case of genodermatosis in this region.

Phospholipid scramblase 1 is secreted by a lipid raft-dependent pathway and interacts with the extracellular matrix protein 1 in the dermal epidermal junction zone of human skin

We examined the interaction of ECM1 (extracellular matrix protein 1) using yeast two-hybrid screening and identified the type II transmembrane protein, PLSCR1 (phospholipid scramblase 1), as a binding partner. This interaction was then confirmed by in vitro and in vivo co-immunoprecipitation experiments, and additional pull-down experiments with GST-tagged ECM1a fragments localized this interaction to occur within the tandem repeat region of ECM1a. Furthermore, immunohistochemical staining revealed a partial overlap of ECM1 and PLSCR1 in human skin at the basal epidermal cell layer. Moreover, in human skin equivalents, both proteins are expressed at the basal membrane in a dermal fibroblast-dependent manner. Next, immunogold electron microscopy of ultrathin human skin sections showed that ECM1 and PLSCR1 co-localize in the extracellular matrix, and using antibodies against ECM1 or PLSCR1 cross-linked to magnetic immunobeads, we were able to demonstrate PLSCR1-ECM1 interaction in human skin extracts. Furthermore, whereas ECM1 is secreted by the endoplasmic/Golgi-dependent pathway, PLSCR1 release from HaCaT keratinocytes occurs via a lipid raft-dependent mechanism, and is deposited in the extracellular matrix. In summary, we here demonstrate that PLSCR1 interacts with the tandem repeat region of ECM1a in the dermal epidermal junction zone of human skin and provide for the first time experimental evidence that PLSCR1 is secreted by an unconventional secretion pathway. These data suggest that PLSCR1 is a multifunctional protein that can function both inside and outside of the cell and together with ECM1 may play a regulatory role in human skin.

Amygdalae and striatum calcification in lipoid proteinosis

Lipoid proteinosis is a rare genodermatosis characterized by multisystem involvement due to intracellular deposition of an amorphous hyaline material. Lipoid proteinosis is caused by mutations in the ECM1 gene. In many patients, skin and mucosa abnormalities are the first manifestation. When the CNS is affected, a wide variety of neurologic abnormalities may be present. The hallmark findings are calcifications, mostly occurring in the amygdalae, hippocampus, parahippocampal gyrus, or even the striatum. Present in half of the patients, moniliform blepharosis is considered a pathognomonic finding. In the other half of patients imaging could assist in the diagnosis. The authors present a series of 3 cases of lipoid proteinosis with brief clinical data and imaging findings.

Lipoid proteinosis

Lipoid proteinosis is a rare disorder with autosomal recessive inheritance, characterized by progressive deposition of hyaline material in the skin, mucous membrane, and different organs of the body, resulting in a multitude of clinical manifestations. A 62-year-old male presented with hoarseness of voice since infancy, eyelid beading, and generalized acneiform scars on the facial skin and extremities, and yellowish papules on his tongue and buccal mucose. The patient was diagnosed clinically as a case of Lipoid proteinosis, which was confirmed by skin and mucosal biopsy. The objective of the present work is to describe this rare entity, with approximately 250 cases found in medical literature. This case report also illustrates that Lipoid proteinosis may show protean clinical features and yet may remain undiagnosed for many years. This report will hopefully spawn further studies that will lead to early diagnosis.

Interaction of extracellular matrix protein 1 with extracellular matrix components: ECM1 is a basement membrane protein of the skin

The extracellular matrix protein 1 (ECM1) is a secreted glycoprotein, which plays an important role in the structural and functional biology of the skin as demonstrated by the identification of loss-of-function mutations in ECM1 as cause of the genodermatosis lipoid proteinosis, characterized by reduplication of the skin basement membrane and hyalinization of the underlying dermis. To search for binding partner(s) of ECM1, we tested the in vitro binding activity of ECM1a, a major isoform of four ECM1 splice variants, to different skin extracellular matrix proteins (such as laminin 332, collagen type IV, and fibronectin) and polysaccharides (such as hyaluronan, heparin, and chondroitin sulfate A) with solid-phase binding assay. We demonstrated that ECM1a utilizes different regions to bind to a variety of extracellular matrix components. Ultrastructurally, ECM1 is a basement membrane protein in human skin and is part of network-like suprastructures containing perlecan, collagen type IV, and laminin 332 as constituents. Furthermore, ECM1a enhanced the binding of collagen IV to laminin 332 dose-dependently, showing its involvement in the dermal-epidermal junction and interstitial dermis and making the functional link to the pathophysiology of lipoid proteinosis. To our knowledge, this is previously unreported.

A failure of mucocutaneous lymphangiogenesis may underlie the clinical features of lipoid proteinosis

Lipoid proteinosis (LiP) (OMIM 247100) is a rare autosomal recessive disease caused by loss of function mutations in the extracellular matrix protein 1 gene, ECM1, on chromosome 1q21. LiP is characterized clinically by hoarseness in early infancy, followed by waxy papules and plaques on the face and body along with pox-like and acneiform scars. We studied a 20-year-old Japanese woman with LiP. She was born of consanguineous parents. Biopsy specimens obtained from a nodule on the elbow were used for histopathology, immunohistology and electron microscopy. Exons 6 and 7 of ECM1 were amplified by polymerase chain reaction (PCR) from genomic DNA from the proband, her parents, her brother and an unrelated person. PCR products were sequenced to detect the mutation. Histopathological examination revealed an irregular mass of calcium beneath deposits of a hyaline material in the dermis. Immunofluorescence double staining showed that the CD31-positive microvascular density was increased but that staining for the lymphatic-specific hyaluronan receptor LYVE-1 was drastically diminished in lesional compared with nonlesional skin of the patient and with normal skin. Electron microscopy revealed marked concentric reduplication of basal laminae not only around blood vessels but also around solitary dermal cells positive for Weibel-Palade bodies scattered in the hyaline material. Sequencing of the PCR products revealed a homozygous frameshift mutation, 507delT, in exon 6. This led to a premature stop codon 23 bp downstream. The results of immunopathological and ultrastructural characterization suggest that a failure of mucocutaneous lymphangiogenesis may underlie the clinical features of LiP. Identification of mutation 507delT in a Japanese patient with LiP further supports the thesis that this mutation represents a recurrent mutation in ECM1 in patients with LiP. To our knowledge, this case represents the first report of calcinosis cutis occurring in LiP.

Extracellular matrix protein 1 inhibits the activity of matrix metalloproteinase 9 through high-affinity protein/protein interactions

Extracellular matrix protein 1 (ECM1), an approximately 85-kDa glycoprotein with broad tissue distribution, harbors mutations in lipoid proteinosis (LP), a heritable disease characterized by reduplication of basement membranes and hyalinization of dermis, associated with neurologic disorders. The mechanisms leading from ECM1 mutations to LP phenotype are unknown. In this study, we explored ECM1 protein-protein interactions utilizing yeast two-hybrid genetic screen of human placental library, which identified nine interacting proteins, including matrix metalloproteinase 9 (MMP9). The interactions were confirmed by beta-galactosidase assay with isolated clones and by co-immunoprecipitation which narrowed the interacting segment in ECM1 to the C-terminal tandem repeat 2 (amino acids 236-361). This peptide segment also inhibited MMP9 activity in a gelatin-based ELISA assay. We propose that ECM1-mediated reduction in MMP9 proteolytic activity may have relevance to pathogenesis of LP.