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.

Lipoid proteinosis.

Lipoid proteinosis is a rare autosomal recessive disorder caused by mutations in ECM1, encoding extracellular matrix protein 1, a glycoprotein expressed in many organs and which has important protein-protein interactions in tissue homeostasis. Although the disease usually presents clinically with warty infiltration of the skin and mucous membranes and a hoarse voice, neuropsychological and neuropsychiatric abnormalities are often prominent features. There may be bean- or comma-shaped intracranial calcifications, often selectively affecting the amygdala. Patients with lipoid proteinosis therefore have been used as models for demonstrating physiologic and pathologic abnormalities of the amygdala with respect to fear processing, affect and cognition, anxiety and memory. Clinically, patients may also have epilepsy, especially involving the temporal lobes. Less common or rare disease associations are headache (including migraine), ataxia, dizziness, schizophrenia, generalized dystonia, transient brachiofacial paralysis, and intracerebral hemorrhage. Beyond the foci of calcification, the cause of the neurologic abnormalities in lipoid proteinosis is unknown, although the ECM1 protein can normally bind to various extracellular matrix proteins and glycosaminoglycans as well as certain enzymes, including matrix metalloproteinase 9. Loss of key protein-protein interactions may underscore some of the disease pathophysiology. There is currently no effective treatment for lipoid proteinosis and clinical care is largely supportive.

Lipoid proteinosis: report of three siblings.

Lipoid proteinosis is a very rare genodermatosis characterized by infiltration of hyaline material into the skin, oral cavity, larynx and internal organs. It usually presents in infancy with hoarseness. Although about 300 cases have been reported in the literature, the occurrence of the disease is rare in siblings. In this report we introduce three siblings with this disease.

Urbach-Wiethe disease: experience at a tertiary care hospital in Abbottabad, Pakistan.

BACKGROUND: Urbache-Wiethe disease (Lipoid Proteinosis) is a rare autosomal recessive disorder characterized by the deposition of an eosinophilic hyaline-like material in the skin, larynx, mucous membranes, brain, and other internal organs. METHODS: A survey of one year duration was carried out prospectively at the Department of Dermatology, Ayub Teaching Hospital Abbottabad to document cases of lipoid proteinosis. Cases were selected from the outpatients department on the basis of clinical presentation and were subjected to detailed examination and investigations after admission. RESULTS: Five cases were diagnosed as suffering from Lipoid Proteinosis over the study period. All had typical features of hoarseness, skin lesions and tongue involvement. All were born of consanguineous parents. Three (60.0%) cases also gave a history of involvement of other family members, particularly cousins. CONCLUSION: This rare disease occurs in Hazara Division of North West Frontier Province of Pakistan with an as yet undetermined frequency and clinical suspicion is warranted to diagnose cases with the typical presentation.

Selected disorders of connective tissue: pseudoxanthoma elasticum, cutis laxa, and lipoid proteinosis.

There has been progress made in the understanding of 3 Mendelian disorders: pseudoxanthoma elasticum, cutis laxa, and lipoid proteinosis cutis and mucosae. While they are primary connective tissue diseases, their names imply a connection to the skin, and in fact, it is often the dermatologist who makes the diagnosis. It seems rational that defects in various extracellular matrix proteins cause lipoid proteinosis or subtypes of cutis laxa, yet the discovery of a liver- and kidney-based transmembrane transporter as the culprit of pseudoxanthoma elasticum was rather surprising and may shed new light on elastic tissue homeostasis.

[Pulmonary alveolar proteinosis]. / Lipoprotéinose alvéolaire pulmonaire.

Pulmonary alveolar proteinosis (PAP) is a rare, diffuse infiltrative lung disease of unknown etiology characterized by accumulation of abnormal lung surfactant in the alveoli and distal airways. Although it was first described in 1958, few large scale studies have been published. The diagnosis is conventionally based on lung biopsy and the value of less invasive procedures such as bronchoalveolar lavage (BAL) remains controversial. A multi-center retrospective study was conducted in an attempt to update epidemiological, clinical and long term outcome and to assess the usefulness of chest CT scan and BAL in the management of a large homogeneous series of 41 patients. Inclusion criteria required a clinical picture compatible with PAP and either histological confirmation, or a BAL with a milky macroscopic appearance coupled with positive staining to PAS. Mean age was 48.8 years with a 4: 1 male predominance. The prevalence of smokers (80%) and occupational exposure to various inhaled dusts (39%) was high. The clinical, roentgenographic and functional features were in keeping with previous series. Worsening dyspnea was the most common symptom. Other common manifestations were dry cough, recurrent lung infections, weight loss, finger clubbing, crackles and cyanosis. LDH serum levels were increased in 51% of cases. Lung function tests usually showed a mild restrictive ventilatory defect with hypoxemia and reduced DLCO. Chest X ray revealed bilateral ground glass opacities with consolidation or air bronchogram involving peri-hilar or lower lobes. Chest CT scan, performed in 38 patients, revealed a similar pattern in most of them with diffuse intra-alveolar ground glass opacities (33/38) and interlobular thickening (35/38), resulting in a crazy paving appearance in the typical geographic pattern (32/38). This latter aspect was highly suggestive of the diagnosis. Segmental BAL led to a definitive diagnosis in 62% and lung biopsy was only required in 38% of cases. These data suggest that careful BAL analysis can be sufficient to provide a diagnosis without the need for a lung biopsy. During follow-up, spontaneous remission or improvement was reported in 26%. Segmental (n=3) or whole lung lavage (n=22) was required in 62.5% with a favorable course (complete remission 37%, improvement 34%, stable course 21%) in 92% of the cases. In this series the overall prognosis for PAP remained good, although unpredictable.

The estimation of selection coefficients in Afrikaners: Huntington disease, porphyria variegata, and lipoid proteinosis.

The effects of mutation, migration, random drift, and selection on the change in frequency of the alleles associated with Huntington disease, porphyria variegata, and lipoid proteinosis have been assessed in the Afrikaner population of South Africa. Although admixture cannot be completely discounted, it was possible to exclude migration and new mutation as major sources of changes in the frequency of these alleles by limiting analyses to pedigrees descendant from founding families. Calculations which overestimated the possible effect of random drift demonstrated that drift did not account for the observed changes in gene frequencies. Therefore these changes must have been caused by natural selection, and a coefficient of selection was estimated for each trait. For the rare, dominant, deleterious allele associated with Huntington disease, the coefficient of selection was estimated to be .34, indicating that this allele has a selective disadvantage, contrary to some recent studies. For the presumed dominant and probably deleterious allele associated with porphyria variegata, the coefficient of selection lies between .07 and .02. The coefficient of selection for the rare, clinically recessive allele associated with lipoid proteinosis was estimated to be .07. Calculations based on a model system indicate that the observed decrease in allele frequency cannot be explained solely on the basis of selection against the homozygote. Thus, this may be an example of a pleiotropic gene which has a dominant effect in terms of selection even though its known clinical effect is recessive.