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Disease Profile
Ichthyosis follicularis atrichia photophobia syndrome
Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
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Age of onset
Infancy
ICD-10
-
Inheritance
Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.
Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.
X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Not applicable
Other names (AKA)
IFAP syndrome
Categories
Congenital and Genetic Diseases; Skin Diseases
Summary
The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
Orpha Number: 2273
Definition
Ichthyosis follicularis alopecia photophobia (IFAP) is a rare genetic disorder characterized by the triad of ichthyosis follicularis, alopecia, and photophobia from birth.
Epidemiology
Prevalence is unknown. Approximately 40 cases have been reported to date. IFAP primarily affects male subjects. Female carriers may develop some clinical features.
All patients present with congenital follicular ichthyosis, alopecia involving the scalp, eyebrows and eyelashes, and photophobia (in the first year of life, infancy or early childhood). Ichthyosis follicularis is characterized by widespread non-inflammatory thorn-like follicular projections. Hyperkeratotic papules are most pronounced over the extensor extremities and scalp and are distributed symmetrically. Non-cicatricial complete body alopecia is also a classical feature. Variable degrees of a collodion membrane may be present in newborns. Psoriasiform plaques, angular cheilitis, periungueal inflammation, dystrophic nails, hypohidrosis and atopic eczema can be present. The palms and soles are generally unaffected. Superficial corneal ulceration and vascularization may lead to progressive corneal scarring. Male patients have relentless progression of corneal vascularization and loss of vision. Atopic keratoconjunctival inflammation, chronic tearing, cataract , horizontal nystagmus , astigmatism and myopia have been reported. In a few cases, mild to severe intellectual disability , short stature , microcephaly , seizures , dysmorphic features (frontal bossing, choanal atresia, large ears), cleft hands, intestinal anomalies (omphalocele, Hirschsprung disease or congenital aganglionic megacolon (see these terms), small intestine stenosis, inguinal hernia), as well as renal, cardiac and vertebral anomalies can be present. Recurrent infections are common. External genitalia are generally normal with a few cases of cryptorchidism and one with hypospadias. Affected or carrier females may have milder symptoms (cutaneous hyperkeratotic lesions that follow the lines of Blaschko, asymmetric distribution of body hair, patchy alopecia).
The disorder is caused by mutations in the MBTPS2 gene (Xp22.12-p22.11) leading to impaired cholesterol homeostasis and response to endoplasmic reticulum stress.
Diagnosis is based on the clinical features and on testing of the MBTPS2 gene.
Differential diagnosis includes dermotrichic syndrome , hereditary mucoepithelial dysplasia, keratitis-ichthyosis-deafness (KID syndrome) and keratosis follicularis spinulosa decalvans (see these terms).
IFAP cannot be detected prenatally by ultrasound .
If the mutation has been identified in a carrier mother, prenatal diagnosis can be proposed. Transmission is X-linked recessive . The mutation might also arise de novo . A few cases of autosomal dominant inheritance have been reported.
Management and treatment
Follicular hyperkeratosis can be treated using topical keratolytics, emollients and urea preparations. A moderate response to acitretin therapy has been found in some patients. Intensive lubrication of the ocular surface is essential. Corneal vascularization does not respond to topical corticosteroids .
Prognosis is variable. Some patients die in the neonatal period while others have normal life expectancy. However, in most patients, progressive loss of vision leads to loss of autonomy. Cardiopulmonary complications are the main cause of death.
Visit the Orphanet disease page for more resources.
Symptoms
This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.