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Disease Profile

Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy

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.

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US Estimated

Europe Estimated

Age of onset

Adolescent

ICD-10

E75.2

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

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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.

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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.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

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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.

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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.

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Not applicable

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Other names (AKA)

PLOSL; Nasu-Hakola disease; NHD;

Categories

Congenital and Genetic Diseases; Musculoskeletal Diseases; Nervous System Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 2770

Definition
Nasu-Hakola disease (NHD), also referred to as polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), is a rare inherited leukodystrophy characterized by progressive presenile dementia associated with recurrent bone fractures due to polycystic osseous lesions of the lower and upper extremities.

Epidemiology
Over 200 cases have been reported worldwide in the literature, the majority of them being in the Japanese and Finnish population. The prevalence in Finland is estimated between 1/500,000 and 1/1,000,000.

Clinical description
The disease course is generally divided into four stages: latent, osseous, early neurologic, and late neurologic. After a normal development during childhood (latent stage), the disease starts manifesting during adolescence or young adulthood (typical age of onset 20-30 years) with pain in the hands, wrists, ankles, and feet. Patients then start suffering from recurrent bone fractures due to polycystic osseous and osteoporotic lesions in the limb bones (osseous stage). During the third or fourth decade of life (early neurologic stage), patients present with pronounced personality changes (e.g. euphoria, lack of concentration, loss of judgment and social inhibitions) characteristic of a frontal lobe syndrome. Patients also typically suffer from initially mild, but progressive, memory disturbances. Epileptic seizures are frequently observed. Finally (late neurologic stage), patients progress to a profound dementia, are unable to speak and move, and usually die by the age of 50 years. Occasionally, the disease presents a different course with the neurologic symptoms preceding the osseous ones.

Etiology
NHD is due to mutations in either the TYROBP or TREM2 genes encoding the tyrosine kinase binding adaptor protein and the triggering receptor expressed on myeloid cells 2 respectively. These genes encode components of a signaling complex involved in the regulation of immune responses, the differentiation of dendritic cells and osteoclasts, and in the phagocytic activity of microglia. The exact pathogenic mechanism is unknown.

Diagnostic methods
Diagnosis is based on clinical and radiologic examination. X-ray imaging shows multifocal cystic lesions on the bones of hands, wrists, feet and ankles. Brain computed tomography (CT) or magnetic resonance imaging (MRI) shows frontally accentuated atrophy of the cerebral white matter. Bilateral calcifications of the basal ganglia are typical. EEG is normal in the early stages but shows diffuse slowing and irritative activity in late stages. Histopathologically, loss of axons and myelin as well as fibrillary gliosis are observed. Molecular genetic testing confirms the diagnosis in ambiguous cases.

Differential diagnosis
The combination of frontal-type dementia starting in the fourth decade and radiologically demonstrable polycystic osseous lesions is unique and facilitates the differentiation of NHD from other forms of familial and non-familial frontotemporal dementia such as frontotemporal dementia and parkinsonism linked to chromosome 17 (see this term).

Antenatal diagnosis
Due to the low carrier frequency of the mutation in the general population, prenatal diagnostic procedures are usually not reasonable, except in genetic isolates.

Genetic counseling
Transmission is autosomal recessive. Children of an NHD patient are healthy carriers of the mutation unless they have also inherited a disease-causing mutation in the TYROBP or TREM2 genes from the other parent. Presymptomatic testing is commercially available.

Management and treatment
There is no curative treatment for the disease. Management is supportive. Antiepileptic drugs are prescribed to prevent seizures. A regular orthopedic and neurologic surveillance is recommended.

Prognosis
NHD is a progressive disease that is fatal usually during the fifth decade of life.

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.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal adipose tissue morphology
Abnormality of adipose tissue
Abnormality of fat tissue
Abnormality of fatty tissue

[ more ]

0009124
Abnormality of epiphysis morphology
Abnormal shape of end part of bone
0005930
Arthralgia
Joint pain
0002829
Bone cyst
Bone cysts
0012062
Bone pain
0002653
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells
0002120
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood

[ more ]

0002376
Disinhibition
0000734
Frontal lobe dementia
0000727
Irritability
Irritable
0000737
Limitation of joint mobility
Decreased joint mobility
Decreased mobility of joints
Limited joint mobility
Limited joint motion

[ more ]

0001376
Memory impairment
Forgetfulness
Memory loss
Memory problems
Poor memory

[ more ]

0002354
Personality changes
Personality change
0000751
Reduced bone mineral density
Low solidness and mass of the bones
0004349
Skeletal dysplasia
0002652
Ventriculomegaly
0002119
30%-79% of people have these symptoms
Agnosia
0010524
Cerebral calcification
Abnormal deposits of calcium in the brain
0002514
Chorea
0002072
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment

[ more ]

0002167
Oculomotor apraxia
0000657
Seizure
0001250
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
5%-29% of people have these symptoms
Acute leukemia
0002488
Functional abnormality of the gastrointestinal tract
0012719
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Percent of people who have these symptoms is not available through HPO
Abnormal foot morphology
Abnormal feet structure
Abnormality of the feet
Abnormality of the foot
Foot deformities
Foot deformity

[ more ]

0001760
Abnormal upper motor neuron morphology
Abnormal shape of upper motor neuron
0002127
Abnormality of the hand
Abnormal hands
Hand anomalies
Hand deformities

[ more ]

0001155
Aggressive behavior
Aggression
Aggressive behaviour
Aggressiveness

[ more ]

0000718
Apraxia
0002186
Autosomal recessive inheritance
0000007
Axonal loss
0003447
Babinski sign
0003487
Basal ganglia calcification
0002135
Caudate atrophy
0002340
Cerebral atrophy
Degeneration of cerebrum
0002059
EEG abnormality
0002353
Euphoria
0031844
Gait disturbance
Abnormal gait
Abnormal walk
Impaired gait

[ more ]

0001288
Gliosis
0002171
Hypoplasia of the corpus callosum
Underdevelopment of part of brain called corpus callosum
0002079
Inappropriate behavior
0000719
Lack of insight
0000757
Leukoencephalopathy
0002352
Myoclonus
0001336
Pathologic fracture
Spontaneous fracture
0002756
Peripheral demyelination
0011096
Primitive reflex
0002476
Urinary incontinence
Loss of bladder control
0000020

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy. Click on the link to view a sample search on this topic.