TaoMedAI/RareMedData huggingface dataset:
Fructose-1,6-bisphosphatase deficiency (ORPHA:348)
Fructose-1,6-biphosphatase (FBP) deficiency is a disorder of fructose metabolism (see this term) characterized by recurrent episodes of fasting hypoglycemia with lactic acidosis, that may be life-threatening in neonates and infants.
Epidemiology
FBP deficiency birth prevalence has been estimated at 1/147,575 in Italy. This disorder has been reported in Japanese, Asian, European, North American, Arab and Moroccan patients.
Clinical description
FBP deficiency may occur neonatally with hepatomegaly, but it usually presents in infants of 3-4 months of age or early childhood, with manifestations including fast-induced hypoglycemia and metabolic acidosis, episodes of tachypnea/apnea, hypoglycemia, ketosis and lactic acidosis. Episodes are often triggered by catabolic conditions such as prolonged fasting (more than 8 to 10 hours), fructose, sorbitol or glycerol ingestion, vomiting, diarrhea or febrile infectious diseases. Patients are asymptomatic between episodes.
Etiology
FBP deficiency is due to homozygous or compound heterozygous mutations in the FBP1(9q22) gene encoding fructose-1,6-bisphosphatase1, resulting in impaired gluconeogenesis. To date, 11deleterious mutations have been reported.
Diagnostic methods
FBP deficiency diagnosis is based on clinical presentation, along with glycemia and lactacidemia levels. Enzyme activity may be measured in leukocytes, and genetic testing of the FBP1 gene confirms diagnosis.
Differential diagnosis
Differential diagnosis includes glycogen storage disease due to glucose-6-phosphatase deficiency (see this term).
Antenatal diagnosis
Prenatal diagnosis is feasible through molecular analysis of amniocytes or chorionic villous cells.
Genetic counseling
Transmission is autosomal recessive. Genetic counseling should be offered to at-risk couples (both individuals are carriers of a disease-causing mutation) informing them that there is a 25% risk of having an affected child at each pregnancy.
Management and treatment
FBP deficiency management aims at avoiding hypoglycemia and lactic acidosis through frequent feeding, enriched with glucose or maltodextrin, especially in illness associated with fever. Prevention and treatment of metabolic decompensation (with glucose orally or intravenously) is essential. Fasting periods longer than 8 hours should be avoided and infectious episodes should be carefully monitored. Fructose or sucrose should be avoided during acute episodes.
Prognosis
With timely adapted management and proper treatment, FPB deficiency prognosis is excellent, even if this condition may be potentially fatal in the newborn period and early infancy.

                            Last update: 
                            September 2015


                            - Expert reviewer(s): 
                            Pr Philippe LABRUNE
Fryns-Smeets-Thiry syndrome (ORPHA:2058)
A rare, genetic, syndromic intellectual disability disorder characterized by severe psychomotor development delay (without development of primary motor abilities and speech) and severe intellectual disability, associated with marfanoid habitus, joint laxity, bilateral hip luxation, hypotonia, scoliosis, and characteristic facial dysmorphism (i.e. high nasal bridge, sharp nose, short philtrum, large mouth, full lips and maxillary hypoplasia). There have been no further description in the literature since 1994.
FTH1-related iron overload (ORPHA:247790)
A rare disorder of iron metabolism and transport characterized by elevated serum ferritin levels, increased serum iron, increased transferrin saturation, and heavy iron deposition in hepatocytes. Iron deposition has also been indicated in heart and bone marrow, while hematological examination of peripheral blood shows no abnormalities.
Fuchs endothelial corneal dystrophy (ORPHA:98974)
A disorder that is the most frequent form of posterior corneal dystrophy and is characterized by excrescences on a thickened Descemet membrane (corneal guttae), generalized corneal edema, with gradually decreased visual acuity.
Epidemiology
The exact prevalence is not known but extreme geographical variability has been reported. FECD is the most prevalent corneal dystrophy in the USA but has been found to be uncommon in Saudi Arabia and in Singaporean Chinese, and very rare in Japan.
Clinical description
The condition is more common and more severe in women (sex ratio 3-4:1). Patients with FECD are initially asymptomatic. Clinical onset is generally in the 5th or 6th decade of life. Discomfort and painful episodes of recurrent corneal erosions occur, along with gradually developing opacification leading to hazy vision. Over time, discomfort may diminish but severe impairment of visual acuity, and even blindness in elderly patients, may be observed. The clinical course often spans 10 to 20 years. The condition is often associated with cataracts. Microbial keratitis and corneal neovascularization are extremely rare complications. Stromal edema produces a blue-gray haze anterior to Descemet membrane followed by eventual thickening of the entire corneal stroma and development of a ground-glass corneal appearance.
Etiology
The etiology of FECD is unknown, but it seems to be a heterogenous complex inherited disorder caused by the interaction of genetic and environmental factors. Mutations in certain genes have been reported in some cases of FECD. Rare cases of early onset have been related to mutations in the COL8A2 gene (1p34.2-p32.3). Heterozygous mutation in the SLC4A11 gene (20p12) has been reported in some late-onset cases of FECD. Other cases have been mapped to chromosomes 13 (13pter-3q12.13) and 18 (18q21.2- q21.32)(TCF4) and to ZEB1 (10p11.22).
Genetic counseling
Although most patients with FECD lack a positive family history, blood relatives sometimes manifest corneal guttae. FECD may also affect siblings and two or more successive generations, apparently as an autosomal dominant disorder having incomplete penetrance, but a simple autosomal dominant pattern is unlikely.
Management and treatment
Most patients with FECD ultimately require a penetrating keratoplasty or a procedure for repairing the posterior surface of the cornea, such as a deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), or Descemet stripping automated endothelial keratoplasty (DSAEK). Visual acuity is markedly improved after a penetrating keratoplasty, DSEK or DSAEK.

                            Last update: 
                            May 2012


                            - Expert reviewer(s): 
                            Dr Gordon KLINTWORTH
Fuchs heterochromic iridocyclitis (ORPHA:263479)
Fuchs heterochromic iridocyclitis (FHI) is an ocular disease of unknown etiology occurring in a very small percentage (0.5-6.2%) of uvietis cases, characterized by diffuse iris heterochromia or atrophy, keratic precipitates in the absence of synechiae, and in some cases evolving to glaucoma and vitreous opacities.
Fuhrmann syndrome (ORPHA:2854)
Fuhrmann syndrome is mainly characterized by bowing of the femora, aplasia or hypoplasia of the fibulae and poly-, oligo-, and syndactyly.
Epidemiology
It has been reported in 11 patients.
Clinical description
Most of the patients also had a hypoplastic pelvis and hypoplasia of the fingers and fingernails. Some had congenital dislocation of the hip, absence or fusion of tarsal bones, absence of various metatarsals, and hypoplasia and aplasia of the toes. Autosomal recessive inheritance is presumed.
Etiology
The syndrome is caused by a partial loss of WNT7A function (gene mapped to 3p25).
Differential diagnosis
The syndrome is allelic to Schinzel phocomelia (or Al-Awadi-Raas-Rothschild syndrome), which results from null mutations in the same gene.

                            Last update: 
                            September 2006
Fukutin-related limb-girdle muscular dystrophy R13 (ORPHA:206554)
A form of limb-girdle muscular dystrophy characterized by an infantile onset of hypotonia, axial and proximal lower limb weakness (with severe weakness noted after febrile illnesses), cardiomyopathy and normal or reduced intelligence. Hypertrophy of calves, thighs, and triceps have also been reported in some cases.
Full NF2-related schwannomatosis (ORPHA:637)
Neurofibromatosis type 2 (NF2) is a tumor-prone disorder characterized by the development of multiple schwannomas and meningiomas.
Epidemiology
Prevalence (initially estimated at 1: 200,000) is around 1 in 60,000.
Clinical description
Affected individuals inevitably develop schwannomas, typically affecting both vestibular nerves and leading to hearing loss and deafness. The majority of patients present with hearing loss, which is usually unilateral at onset and may be accompanied or preceded by tinnitus. Vestibular schwannomas may also cause dizziness or imbalance as a first symptom. Nausea, vomiting or true vertigo are rare symptoms, except in late-stage disease. The other main tumors are schwannomas of the other cranial, spinal and peripheral nerves; meningiomas both intracranial (including optic nerve meningiomas) and intraspinal, and some low-grade central nervous system malignancies (ependymomas). Ophthalmic features are also prominent and include reduced visual acuity and cataract. About 70% of NF2 patients have skin tumors (intracutaneous plaque-like lesions or more deep-seated subcutaneous nodular tumors).
Etiology
NF2 is caused by mutations in the NF2 gene on chromosome 22. More than 50% of patients represent new mutations and as many as one-third are mosaic for the underlying disease-causing mutation. Although truncating mutations (nonsense and frameshifts) are the most frequent germline event and cause the most severe disease, single and multiple exon deletions are common. A strategy for detection of the latter is vital for a sensitive analysis.
Diagnostic methods
Diagnosis is based on clinical and neuroimaging studies. Presymptomatic genetic testing is an integral part of the management of NF2 families.
Differential diagnosis
The main differential diagnosis of NF2 is schwannomatosis.
Antenatal diagnosis
Prenatal diagnosis and pre-implantation genetic diagnosis is possible.
Genetic counseling
NF2 is a dominantly inherited tumor predisposition syndrome.
Management and treatment
NF2 represents a difficult management problem with most patients facing substantial morbidity and reducedlife expectancy. Surgery remains the focus of current management although watchful waiting with careful surveillance and occasionally radiation treatment have a role.
Prognosis
Prognosis is adversely affected by early age at onset, a higher number of meningiomas and having a truncating mutation.

                            Last update: 
                            June 2009


                            - Expert reviewer(s): 
                            Pr Gareth EVANS  - Pr D GARETH
Full schwannomatosis (ORPHA:93921)
A rare form of neurofibromatosis characterized by the development of multiple schwannomas (nerve sheath tumors), without involvement of the vestibular nerves, and often associated with chronic pain. Dysesthesia and paresthesia may also be present. Common localizations include the spine, peripheral nerves, and the cranium.
Fulminant viral hepatitis (ORPHA:35063)
Fulminant viral hepatitis is a rapid and severe impairment of liver functions (acute liver failure) with hepatic encephalopathy developing less than 8 weeks after the onset of jaundice, secondary to viral hepatitis mainly due to HBV, but also to HAV.
Functioning gonadotropic adenoma (ORPHA:91348)
Functioning gonadotropic adenoma is a very rare pituitary tumor, macroscopically characterized by a soft, well vascularized, variable sized adenoma, with occasional areas of hemorrage or necrosis, that secretes biologically active gonadotropins. In addition to common neurological signs due to mass effect (headache and/or visual field deterioration), additional clinical manifestations include menstrual irregularities (secondary amenorrhea, oligomenorhea or severe menorrhagia), galactorrhea, infertility or ovarian hyperstimulation syndrome (in premenopausal women), testicular enlargement and, occasionally, hypogonadism (in men) and isosexual precocious puberty (in children).
Fundus albipunctatus (ORPHA:227796)
Fundus albipunctatus is a rare, genetic retinal dystrophy disorder characterized by the presence of numerous small, round, yellowish-white retinal lesions that are distributed throughout the retina but spare the fovea. Patients present in childhood with non-progressive night blindness with prolonged cone and rod adaptation times. The macula may or may not be involved, which may result in a decrease of central visual acuity with age.
Fundus pulverulentus (ORPHA:99004)
Fundus pulverulentus is a rare form of patterned dystrophy of the retinal pigment epithelium characterized by a granular appearance in the macula, with coarse and punctiform mottling of the retinal pigment epithelium within the macular region. Association with choroidal neovascularization has been reported.
Fungal keratitis (ORPHA:519930)
A rare disorder of the anterior segment of the eye characterized by ocular infection by human-pathogenic fungi, most commonly Aspergillus, Candida, or Fusarium species, which gain access into the corneal stroma through a defect in the corneal epithelium. Risk factors include trauma, ocular surface disease, contact lenses, or immunocompromised state. Patients present with pain, foreign body sensation, redness, photophobia, tearing, secretion, or blurred vision. The condition may be complicated by corneal destruction and perforation, endophthalmitis, scleritis, and panophthalmitis.
Fungal myositis (ORPHA:207000)
A rare acquired skeletal muscle disease characterized by inflammation of a muscle due to infection with a fungus, usually occurring in an immunocompromised host. General symptoms are pain, tenderness, swelling, and/or weakness in the affected muscle. Most common causative agent are Candida species, with myositis developing in the setting of systemic candidiasis, typically as diffuse, multiple microabscesses. Other fungal pathogens potentially causing myositis are Cryptococcus neoformans, Histoplasma capsulatum, Coccidioides species, or Aspergillus species, among others.
Furuncular myiasis (ORPHA:591)
A parasitic disease characterized by infestation of the skin with larvae of a variety of fly species. Furuncular myiasis specifically involves flies whose eggs are able to breach healthy skin, which concerns three species: Cordylobia anthropophaga (also called the African tumbu fly or Cayor worm for the larvae) and Cordylobia rodhaini (the Lund's fly), and Dermatobia hominis (the human botfly).
Epidemiology
There is no solid data for the incidence of this tropical disease but the cases reported in Europe occur following visits to affected regions (Latin America, Sub-Saharan Africa) or in association with animal importation. The disease is probably underdiagnosed and its incidence underestimated.
Clinical description
Furuncular myiasis only occur on healthy skin. The lesion looks like a bacterial furuncle. However, the head of the larva can be spotted through the central cavity. The patient often reports an intense pain and a feeling of creeping in his skin. The lesion occurs on uncovered areas (lower and upper limbs, head and neck mostly), usually during the rainy season. Infection becomes obvious within 10 to 15 days with the formation of a pseudo-furuncle or emergence of a maggot.
Etiology
Furuncular myiasis can be observed in most countries of Africa and South America, and is not uncommon among international travelers. In the case of Cordylobia anthropophaga and Cordylobia rodhaini, the females lay their eggs on damp fabric or on the ground. The larvae penetrate the skin following contact with the ground or with non-ironed contaminated fabric. Dermatobia hominis is found in Latin America. The egg is laid by the fly under the abdomen of a mosquito, through a phoresis process. The egg is then inoculated to a human during a mosquito bite. Poverty, lack of hygiene and proximity with animals are risk factors. Though primarily affecting low-resources populations in hot humid areas, the disease can also happen in wealthy individuals during outdoor activities in endemic countries.
Diagnostic methods
The diagnosis relies on clinical examination. Ultrasound is rarely performed but can be useful in referral centers.
Differential diagnosis
Differential diagnosis includes furunculosis, abscess, insect bite, prurigo, cutaneous cyst and tungiasis.
Management and treatment
The treatment relies on manual extraction of the larva. It can be achieved by pressing around the lesions with two or four fingers. A punch biopsy can be used if the manual extraction is impossible. When available, intravenous ivermectin can be injected in the lesion cavity to kill the larva and make the extraction easier. Oral ivermectin is not useful. The larva should be extracted as a whole in order to leave no foreign body in the skin. Antibiotics should be used only in case of clinical secondary infection. Tetanus immunization status should be checked.
Prognosis
The condition is not life-threatening and easily treated.

                            Last update: 
                            June 2023


                            - Expert reviewer(s): 
                            Dr Romain BLAIZOT
Fusariosis (ORPHA:228119)
Fusariosis describes a superficial, locally invasive, disseminated infection with the pathogenic fungus species, Fusarium, often found in soil and water, which is mainly transmitted to humans through traumatic inoculation and that manifests with keratitis, onychomycosis and less frequently peritonitis and cellulitis. In the immunocompromised, disseminated fusariosis is more common and it manifests with refractory fever, skin lesions (ecthyma-like, target, and multiple subcutaneous nodules), severe myalgias and sino-pulmonary infections.
Fused mandibular incisors (ORPHA:2287)
Fused manidbular incisors is an extremely rare dental anomaly that is characterized by the union of two, normally separated, incisor tooth germs of the primary dentition. It is frequently associated with hypodontia (see this term) and an increased risk of pulp exposure.
Gabriele-de Vries syndrome (ORPHA:506358)
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by variable developmental delay and intellectual disability, movement disorder or gait abnormalities, and dysmorphic craniofacial features (such as facial asymmetry, broad forehead, posteriorly rotated ears, thick lower lip, micrognathia, or cleft palate). A variety of congenital malformations have been reported in addition, including ocular, renal, cardiac, and joint anomalies, among others. Some patients show behavioral alterations (autism, hyperactivity, or anxiety).
Gaisböck syndrome (ORPHA:90041)
Gaisbock syndrome is characterised by secondary polycythemia.
Epidemiology
It occurs mainly in male sedentary individuals, on a high-calorie diet. Prevalence is unknown.
Clinical description
The clinical picture includes mild obesity, hypertension and decrease in plasma volume with relative increase in hematocrit, blood viscosity, serum cholesterol, triglycerides and uric acid. The reduction in plasma volume seems related to the elevation of the diastolic blood pressure.
Prognosis
Prognosis is impaired by the development of cardiovascular complications.

                            Last update: 
                            December 2007
Galactokinase deficiency (ORPHA:79237)
A rare mild form of galactosemia characterized by early onset of cataract and an absence of the usual signs of classic galactosemia, i.e. feeding difficulties, poor weight gain and growth, lethargy, and jaundice.
Epidemiology
Prevalence of this form of galactosemia is not known but is estimated to be less than 1/ 100,000.
Clinical description
Patients with galactokinase deficiency generally have elevated plasma galactose and increased urinary excretion of galactitol. They develop cataracts during the first weeks or months of life as a result of accumulation of galactitol in the lens. Patients are otherwise healthy.
Etiology
Galactokinase deficiency is caused by mutations in the GALK1 gene (17q24) coding for the galactokinase enzyme.
Genetic counseling
The disorder is inherited in an autosomal recessive manner.
Prognosis
Development of cataracts appears to be fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.

                            Last update: 
                            December 2011


                            - Expert reviewer(s): 
                            Pr M.E. [Estela] RUBIO-GOZALBO
Galactose epimerase deficiency (ORPHA:79238)
A very rare, moderate to severe form of galactosemia characterized by moderate to severe signs of impaired galactose metabolism.
Epidemiology
Overall prevalence is not known but the disorder is thought to be very rare. Annual incidence is not known.
Clinical description
The disorder represents a continuum from peripheral to generalized states with corresponding disease severity. When ingesting breast milk or lactose-containing formula, patients may develop hypotonia, poor feeding, vomiting, weight loss, jaundice, hepatomegaly, splenomegaly, liver disorders, aminoaciduria, impaired growth, cataracts and cognitive deficiency. In severe cases, the disease can be life-threatening.
Etiology
Galactose epimerase deficiency is caused by mutations in the GALE gene (1p36) encoding the UDP-galactose 4-epimerase enzyme.
Genetic counseling
Galactose epimerase deficiency is inherited in an autosomal recessive manner.
Prognosis
Occurrence of these symptoms can be resolved or prevented by implementing a galactose-restricted diet.

                            Last update: 
                            December 2011


                            - Expert reviewer(s): 
                            Pr M.E. [Estela] RUBIO-GOZALBO
Galactose mutarotase deficiency (ORPHA:570422)
A rare disorder of galactose metabolism characterized by persistent congenital galactosemia due to deficiency of the enzyme galactose mutarotase. Patients may present bilateral cataract, while gastrointestinal symptoms or severe liver dysfunction are absent. The natural history of the disease is unknown. Severe complications, such as neurological symptoms, have not been reported under early treatment with a galactose-restricted diet.