TaoMedAI/RareMedData huggingface dataset:
Kaposiform hemangioendothelioma (ORPHA:2122)
A rare low-grade malignant cutaneous or visceral vascular tumour that may be associated with severe thrombopaenia with consumption coagulopathy (Kasabach-Merritt syndrome) in pediatric patients.
Epidemiology
The prevalence is unknown.
Clinical description
Kaposiform haemangioendothelioma may develop at any age, but is most common during infancy. Congenital forms have also been described. Depending on the initial site of development, the vascular tumours present as sensitive blue-purple infiltrated plaques, palpable masses or as a tumour compression syndrome (retroperitoneal, severe cervical or mediastinal forms). The majority of reported cases concern the complicated visceral forms. Superficial forms appear to be less common. Cutaneous forms show clinical similarities to tufted angiomas, or graft on to diffuse lymphatic malformations (lymphangiomas). Osseous and regional lymph node involvement has been reported but metastasis does not appear to be a feature of this disease.
Etiology
The etiology is unknown.
Diagnostic methods
The diagnosis is based on the results of histological studies (after definition of the boundaries by magnetic resonance imaging, MRI), which reveal nodules and dense nests of fusiform cells with slight cellular atypia and mitotic activity, frequent slit-like vascular spaces and positive immunostaining for the D2-40 lymphatic marker.
Differential diagnosis
The differential diagnoses include Kaposi's sarcoma and tufted angioma. The clinical similarities with tufted angioma, the association of both conditions with Kasabach-Merritt syndrome and the histological features of these syndromes have led to the suggestion that kaposiform haemangioendothelioma and tufted angioma are part of the same clinical spectrum of vascular tumours.
Antenatal diagnosis
Prenatal diagnosis is possible for voluminous forms of kaposiform haemangioendothelioma through detection of highly vascularised masses on foetal ultrasound, followed by foetal MRI. However, precise diagnosis of the tumour type can only be made by biopsy after the birth.
Management and treatment
Treatment depends of the form of disease present: treatment of non-complicated cutaneous forms differs from that for forms associated with Kasabach-Merritt syndrome. Non-complicated cutaneous forms presenting as relatively small lesions may be treated by local corticotherapy, whereas diffuse invalidating forms may require alpha 2b-interferon therapy or vincristine administration. Therapeutic options for forms associated with Kasabach-Merritt syndrome include pharmacological treatment (systemic corticotherapy, vincristine, alpha 2b-interferon, polychemotherapy and a combination of ticlopidine, asprin and pentoxyphilline), embolisation, surgical excision and radiotherapy.
Prognosis
The prognosis depends on the chronicity of the lesions and extent of the complications (severity of the form present and association with Kasabach-Merritt syndrome).

                            Last update: 
                            September 2006


                            - Expert reviewer(s): 
                            Dr Odile ENJOLRAS
Kaposiform lymphangiomatosis (ORPHA:464329)
A rare vascular anomaly or angioma characterized by multifocal malformed lymphatic channels lined by clusters or sheets of spindled lymphatic endothelial cells with a predilection for the thoracic cavity, but also involving extra-thoracic locations, especially bones and spleen. Typical clinical signs and symptoms are pericardial and pleural effusions, cough, dyspnea, bleeding, and fractures secondary to bone involvement. Prognosis is generally poor due to the progressive nature of the condition.
Kapur-Toriello syndrome (ORPHA:2328)
Kapur-Toriello syndrome is an extremely rare syndrome characterized by facial dysmorphism, severe intellectual deficiency, cardiac and intestinal anomalies, and growth retardation.
Epidemiology
Only four cases have been reported in the literature, in three unrelated families.
Clinical description
Dysmorphic features include bilateral cleft lip and palate, bulbous nasal tip and eye anomalies.
Genetic counseling
The condition seems to be inherited as an autosomal recessive trait.

                            Last update: 
                            February 2010
Karsch-Neugebauer syndrome (ORPHA:2329)
Karsch-Neugebauer syndrome is a rare syndrome characterized by split-hand and split-foot deformity and ocular abnormalities, mainly a congenital nystagmus.
Epidemiology
Ten cases from four families have been reported in the literature.
Clinical description
In some cases the hands are monodactylous. The affected patients have normal mental development.
Genetic counseling
The condition seems to be autosomal dominant with a relatively high proportion of gonadal mosaicism.

                            Last update: 
                            September 2010
Karyomegalic interstitial nephritis (ORPHA:401996)
A rare, genetic renal disease characterized by slowly progressive, chronic, tubulointerstitial nephritis, leading to end-stage renal disease before the age of 50 years, manifesting with mild proteinuria, glucosuria and, occasionally, urinary sediment abnormalities (mainly hematuria). Mild extrarenal manifestations, such as recurrent upper respiratory tract infections and abnormal liver function tests, may be associated. Renal biopsy reveals severe, chronic, interstitial fibrosis and tubular changes, as well as hallmark karyomegalic tubular epithelial cells which line the proximal and distal tubules and have enlarged, hyperchromatic nuclei.
Kasabach-Merritt phenomenon (ORPHA:2330)
A rare hemorrhagic disorder characterized by potentially life-threatening thrombocytopenia, microangiopathic hemolytic anemia, and consumptive coagulopathy in the context of kaposiform hemangioendothelioma or tufted angioma.
KCNQ2-related epileptic encephalopathy (ORPHA:439218)
KCNQ2-related epileptic encephalopathy is a severe form of neonatal epilepsy that usually manifests in newborns during the first week of life with seizures (that affect alternatively both sides of the body), often accompanied by clonic jerking or more complex motor behavior, as well as signs of encephalopathy such as diffuse hypotonia, limb spasticity, lack of visual fixation and tracking and mild to moderate intellectual deficiency. The severity can range from controlled to intractable seizures and mild/moderate to severe intellectual disability.
KDM5C-related syndromic X-linked intellectual disability (ORPHA:85279)
A rare multiple congenital anomalies/dysmorphic syndrome characterized by mild to severe intellectual deficit associated with variable clinical manifestations including spasticity, cryptorchidism, maxillary hypoplasia, alopecia areata, epilepsy, short stature, impaired speech, and behavioral problems.
Keipert syndrome (ORPHA:2662)
A rare multiple congenital anomalies syndrome characterized by facial dysmorphism (hypertelorism, broad and high nasal bridge, depressed nasal ridge, short columella, underdeveloped maxilla, and prominent cupid-bow upper lip vermillion), mild to severe congenital sensorineural hearing loss, and skeletal abnormalities consisting of brachytelephalangy and broad thumbs and halluces with large, rounded epiphyses. Additional manifestations that have been reported include pulmonary valve stenosis, voice hoarseness and renal agenesis.
Kenny-Caffey syndrome (ORPHA:2333)
A rare primary bone dysplasia syndrome characterized by growth retardation with proportionate short stature, cortical thickening and medullary stenosis of the long bones, delayed anterior fontanelle closure, hypocalcemia due to congenital hypoparathyroidism and facial dysmorphism, including prominent forehead, microphthalmia, and micrognathia. Additional manifestations include ocular and dental anomalies (e.g. corneal opacity, hyperopia, optic atrophy, tortuous retinal vessels, dental caries, enamel defects) and, occasionally, hypoplastic nails and neonatal liver disease. Inheritance may be autosomal dominant or autosomal recessive, with more severe growth retardation, small hands and feet, intellectual disability, microcephaly and recurrent bacterial infections being observed in the latter.
Keppen-Lubinsky syndrome (ORPHA:435628)
A rare, genetic, primary lipodystrophy syndrome characterized by severe developmental delay and intellectual disability, hypertonia, hyperreflexia, microcephaly, tightly adherent skin, an aged appearance, severe generalized lipodystrophy, and distinct facial dysmorphism which includes large prominent eyes, narrow nasal bridge, tented upper lip vermilion, an open mouth, and high-arched palate. Laboratory analysis of serum and urine are normal.
Keratinopathic ichthyosis (ORPHA:281103)
A group of rare inherited non-syndromic ichthyoses characterized by mutations in keratin genes. Mutations in KRT1 and KRT10 cause most cases of epidermolytic ichthyosis (EI), as well as congenital reticular ichthyosiform erythroderma (CRIE). EI manifests at birth with generalized blistering, which later transforms into hyperkeratosis. Severe palmoplantar involvement is suggestive of the presence of a KRT1 mutation. CRIE patients present at birth with erythroderma and scaling, often with a collodion membrane, and gradually develop confetti-like clear areas of normal skin. KRT2 mutations are associated with superficial epidermolytic ichthyosis (SEI), which is clinically similar to EI, but generally milder and more localized.
Keratocystic odontogenic tumor (ORPHA:447777)
A rare odontogenic tumor characterized by an unilocular or multilocular cyst most commonly located in the posterior body and lower ramus of the mandible, often surrounding the crown of the third molar. Histopathologically, the lesion shows a lining of parakeratinized stratified squamous epithelium with palisading hyperchromatic basal cells. Patients may be asymptomatic or present with local infection and/or signs and symptoms of mass effect. Recurrence is rare after complete surgical removal. Some patients have multiple cysts (metachronous or synchronous), especially in the context of nevoid basal cell carcinoma syndrome (Gorlin syndrome).
Keratoderma hereditarium mutilans with ichthyosis (ORPHA:79395)
A rare diffuse, mutilating, hereditary palmoplantar keratoderma characterized by severe, honeycomb-pattern palmoplantar keratosis and pseudoainhum of the digits leading to autoamputation, associated with mild to moderate congenital sensorineural hearing loss. Additional features include stellate keratosis on the extensor surfaces of the fingers, feet, elbows and knees. Alopecia, onychogryphosis, nail dystrophy or clubbing, spastic paraplegia and myopathy may also be associated.
Keratoderma hereditarium mutilans (ORPHA:494)
Keratoderma hereditarium mutilans is a rare, diffuse, mutilating, hereditary palmoplantar keratoderma disorder characterized by severe, honeycomb-pattern palmoplantar keratosis and pseudoainhum of the digits leading to autoamputation, associated with mild to moderate congenital sensorineural hearing loss. Additional features include stellate keratosis on the extensor surfaces of the fingers, feet, elbows and knees. Alopecia, onychogryphosis, nail dystrophy or clubbing, spastic paraplegia and myopathy may also be associated.
Keratolytic winter erythema (ORPHA:50943)
Keratolytic winter erythema is a rare epidermal disease, characterized by recurrent centrifugal palmoplantar peeling and erythema presenting seasonal variation (cold weather). Skin lesions may spread to the dorsum of hands and feet and to the interdigital spaces. Lower legs, knees and thighs may also be involved. Episodes may be preceded by itch and hyperhidrosis. Skin biopsy reveals an epidermal spongiosis with clefting in the stratum corneum, followed by regrowth. Keratolytic winter erythema follows an autosomal dominant mode of transmission.
Keratosis follicularis spinulosa decalvans (ORPHA:2340)
Keratosis follicularis spinulosa decalvans is a rare genodermatosis occurring during infancy or childhood, predominantly affecting males, and characterized by diffuse follicular hyperkeratosis associated with progressive cicatricial alopecia of the scalp, eyebrows and eyelashes. Additional findings can include photophobia, corneal dystrophy, facial erythema, and/or palmoplantar keratoderma.
Keratosis follicularis-dwarfism-cerebral atrophy syndrome (ORPHA:2339)
A rare, genetic, developmental defect during embryogenesis syndrome characterized by generalized keratosis follicularis, severe proportionate dwarfism and cerebral atrophy. Alopecia (of scalp, eyebrows and eyelashes) and microcephaly are additionally observed features. Intellectual disability, inguinal hernia and epilepsy may also be associated. There have been no further descriptions in the literature since 1974.
Keratosis linearis-ichthyosis congenita-sclerosing keratoderma syndrome (ORPHA:281201)
Keratosis linearis-ichthyosis congenita-sclerosing keratoderma syndrome is an inherited epidermal disorder characterized by palmoplantar keratoderma, linear hyperkeratotic papules on the flexural side of large joints (cord-like distribution around wrists, in antecubital and popliteal folds), hyperkeratotic plaques (on neck, axillae, elbows, wrists, and knees), mild ichthyosiform scaling, and sclerotic constrictions around fingers that present flexural deformities.
Keratosis palmaris et plantaris-clinodactyly syndrome (ORPHA:86919)
Keratosis palmaris et plantaris-clinodactyly syndrome is characterised by the association of palmoplantar keratosis with clinodactyly of the fifth finger. Less than 20 cases have been described in the literature so far, and the majority of reported patients were of Mexican origin. Transmission is autosomal dominant.
Kerion celsi (ORPHA:499)
A rare inflammatory and suppurating type of tinea capitis, a skin infection caused by Trichophyton or Microsporum fungi, that predominantly affects the scalp and that is characterized by the development of painful crusty lesions covered with follicular pustules and surrounded by erythematous alopecic areas, that can later evolve into abscesses and leave permanent cicatricial alopecia. Lesions can be associated with regional lymphadenopathy.
Ketamine-induced biliary dilatation (ORPHA:293807)
Ketamine-induced biliary dilatation is an acquired biliary tract disease caused by the abusive consumption of ketamine, which results in the fusiform dilatation of the common bile ducts (CBD) without obstructive lesions or dilatation of the intrahepatic biliary ducts. Possible manifestations of the underlying cholangiopathy include epigastric pain and impaired liver function. Severity of CBD dilatation appears to correlate with the duration of ketamine consumption and the condition has been reported to be reversible in abstinent patients.
Ketoacidosis due to monocarboxylate transporter-1 deficiency (ORPHA:438075)
A rare disorder of ketone body transport characterized by recurrent episodes of ketoacidosis provoked by fasting or infections in the first years of life. The episodes are typically preceded by poor feeding and vomiting and are associated with dehydration, in severe cases also with decreased consciousness and insufficient respiratory drive. Hypoglycemia is observed only infrequently. Patients with homozygous mutations tend to present at a younger age, have more profound ketoacidosis, and may show mild to moderate developmental delay in addition.
Keutel syndrome (ORPHA:85202)
A rare multiple congenital anomalies/dysmorphic syndrome characterized by diffuse cartilage calcification, brachytelephalangism, peripheral pulmonary artery stenoses and facial dysmorphism. Vascular calcification has been reported in some cases.
Epidemiology
More than 40 cases have been reported in the literature so far, with the majority of patients being diagnosed during childhood or earlier.
Clinical description
The abnormal calcification principally involves the cartilage of the ears, nose, larynx and the tracheobronchial tree. Epiphyseal stippling of the long bones and calcification of the spinal column vertebrae have also been reported. The facial dysmorphism is characterized by maxillary and midface hypoplasia (broad and depressed nasal bridge with small alae nasi). Other associated features may include hearing loss and recurrent otitis and/or sinusitis, mild intellectual deficit, seizures/epilepsy, frequent respiratory infections, nasal speech and short stature. Patients may show vascular calcification, cerebral calcification, moyamoya and arterial stenosis. Additional findings of white matter anomalies, encephalomalacia, optic nerve atrophy, and lax and doughy skin with prominent skin folds were reported in one affected family.
Etiology
The syndrome is caused by mutations in the gene encoding the matrix Gla protein (MGP, located at 12p13.1-p12.3).
Diagnostic methods
Diagnosis is usually suspected on the basis of the clinical presentation and radiographic examination, with abnormal cartilage calcification and brachytelephalangism being the cardinal signs of the syndrome. The diagnosis can be confirmed by gene mutation analysis.
Differential diagnosis
The principle differential diagnosis is X-linked recessive chondrodysplasia punctata, but abnormal calcification has also been observed in children with warfarin embryopathy and in those with combined vitamin K-dependent coagulation factor deficiency.
Antenatal diagnosis
Antenatal diagnosis is possible where the pathogenic variant has previously been identified in a family member.
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
Treatment is symptomatic and may involve angiographic dilatation for peripheral pulmonary artery stenosis and bronchodilating agents to relieve dyspnea and wheezing.
Prognosis
The prognosis for most patients is good, but life expectancy depends on the extent of the pulmonary involvement.

                            Last update: 
                            March 2024


                            - Expert reviewer(s): 
                             Kyoungmi BAK  - Pr Monzur MURSHED
Kidney tubulopathy-dilated cardiomyopathy syndrome (ORPHA:73224)
A rare renal disease characterised by hypokalaemic metabolic alkalosis secondary to a tubulopathy, hypomagnesaemia with hypermagnesuria, severe hypercalciuria and dilated cardiomyopathy.
Kienbock disease (ORPHA:97332)
Kienbock disease is a rare bone disorder of unknown etiology characterized clinically by osteonecrosis of the carpal lunate, eventually leading to collapse of the lunate bone impacting wrist function.
Kimura disease (ORPHA:482)
Kimura disease is a benign and chronic inflammatory disorder of unknown etiology, occurring mainly in Asian countries (very rarely in Western countries) and predominantly affecting young men, that usually presents with solitary or multiple non-tender subcutaneous masses in the head and neck region (in particular the preauricular and submandibular area) and/or generalized painless lymphadenopathy, often with salivary gland involvement. Characteristic laboratory findings include blood eosinophilia and markedly elevated serum immunoglobulin E (IgE) levels. It is often associated with autoinflammatory disorders (i.e. ulcerative colitis, bronchial asthma) and a co-existing renal disease.
King-Denborough syndrome (ORPHA:99741)
King-Denborough syndrome is a rare genetic non-dystrophic myopathy characterized by the triad of congenital myopathy, dysmorphic features and susceptibility to malignant hyperthermia. Patients present with a wide phenotypic range, including delayed motor development, muscle weakness and fatigability, ptosis and facies myopathica (with or without creatine kinase elevations), skeletal abnormalities (e.g. short stature, scoliosis, kyphosis, lumbar lordosis and pectus carinatum/excavatum), mild dysmorphic facial features (e.g. hypertelorism, down-slanting palpebral fissures, epicanthic folds, low set ears, micrognathia), webbing of the neck, cryptorchidism, and a susceptibility to malignant hyperthermia and/or rhabdomyolysis due to intensive physical strain, viral infection or statin use.
KLHL9-related early-onset distal myopathy (ORPHA:399081)
KLHL9-related early-onset distal myopathy is a rare, genetic distal myopathy characterized by slowly progressive distal limb muscle weakness and atrophy (beginning with anterior tibial muscle involvement followed by the intrinsic hand muscles) in association with reduced sensation in a stocking-glove distribution. Patients present with high stepping gait, ankle areflexia and contractures in the first to second decade of life, associated with marked ankle extensor muscle atrophy; later proximal muscle involvement is moderate and ambulation is preserved throughout the life.
Klippel-Feil anomaly-myopathy-facial dysmorphism syndrome (ORPHA:447974)
A rare genetic disease characterized by the association of Klippel-Feil anomaly (fusion of the cervical spine), myopathy, hypotonia, short stature, microcephaly, and facial dysmorphism (including low-set ears, bulbous nose, long philtrum, high-arched palate, and low posterior hairline, among others). Cardiac abnormalities and various skeletal anomalies (such as pectus excavatum or clinodactyly) have also been reported.
Klüver-Bucy syndrome (ORPHA:157823)
A rare neurologic disease characterized by visual agnosia, hyperorality (strong tendency to examine objects orally), hypermetamorphosis (described as the irresistible impulse to notice and react to everything within sight), hypersexuality, changes in dietary habits and hyperphagia, placidity, and amnesia, due to bilateral lesions of the temporal lobe including the hippocampus and amygdala.
Kniest dysplasia (ORPHA:485)
Kniest dysplasia is a severe type II collagenopathy characterized by a short trunk and limbs, prominent joints and midface hypoplasia (round face with a flat nasal root).
Epidemiology
Prevalence is unknown.
Clinical description
The disease is apparent from birth. Cleft palate (sometimes associated with Pierre-Robin syndrome, see this term), kyphoscoliosis, premature osteoarthritis, severe myopia and deafness are common findings. Stature varies but is often severely affected. Intelligence is usually normal.
Etiology
The disease is caused by mutations in the COL2A1 gene (12q13.11-q13.2) encoding type II collagen.
Diagnostic methods
Diagnosis is made on the basis of radiologic features including large and deformed epiphyses, absence of the femoral head, enlargement of the superior metaphysis of the femur, platyspondyly and other vertebral malformations. Pathological studies of the cartilage reveal the presence of intracytoplasmic inclusions in chondrocytes and a highly vacuolated matrix.
Differential diagnosis
Forms of spondyloepiphyseal dysplasia and metatropic dysplasia (see these terms) constitute the principle differential diagnoses. In young patients, clinical and radiological features overlap with those of OSMED (see this term), but in the latter myopia is absent.
Antenatal diagnosis
Molecular prenatal diagnosis is possible for families in which the disease-causing mutation has already been identified. Micromelia may be detected during the second trimester of the pregnancy and fetal CT scan may be a useful tool for diagnosis.
Genetic counseling
The disease is transmitted as an autosomal dominant trait. Most cases are due to de novo heterozygous COL1A2 mutations but affected parents should be informed of a recurrence risk of 50%.
Management and treatment
Management is supportive only.
Prognosis
Prognosis depends on the extent of the joint malformations and vertebral anomalies

                            Last update: 
                            September 2008


                            - Expert reviewer(s): 
                            Dr Martine LE MERRER