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Disease Profile
D-bifunctional protein deficiency
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.
0
Age of onset
Infancy
ICD-10
E71.3
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)
DBP deficiency; Peroxisomal bifunctional enzyme deficiency; PBFE deficiency;
Categories
Congenital and Genetic Diseases; Metabolic disorders
Summary
D-bifunctional
Some researchers have suggested classifying DBP deficiency into three subtypes, depending on how severely the mutation in the HSD17B4 gene affects the function of the gene and the protein that it codes for. Almost all individuals with types I, II, and III have similar signs and symptoms. A fourth subtype has additionally been proposed for individuals that have less severe symptoms.[2]
While there is no cure for DBP deficiency, treatment is focused on improving nutrition and growth, controlling symptoms, and limiting the progression of liver disease.[3]
Symptoms
- Eye problems (
nystagmus ,strabismus , failure to focus on objects, optic nerve atrophy,cataracts , and/or progressive vision loss) - Progressive
hearing loss - Failure to achieve or loss of developmental milestones
- Distinct facial features (high forehead, high arched roof of the mouth (palate), enlarged soft spot (fontanelle), long philtrum, epicanthal folds, widely spaced eyes (hypertelorism), macrocephaly, retrognathia, and low-set ears)
- Enlarged liver (hepatomegaly)
- Brain abnormalities (polymicrogyria, damage to the protective covering of the brain (demyelination))
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
|
---|---|---|
1%-4% of people have these symptoms | ||
Cerebral hypoplasia |
Small cerebrum
Underdeveloped cerebrum
[ more ] |
0006872 |
Decreased nerve conduction velocity | 0000762 | |
Percent of people who have these symptoms is not available through HPO | ||
Abnormal facial shape |
Unusual facial appearance
|
0001999 |
Aplasia/Hypoplasia of the cerebellum |
Absent/small cerebellum
Absent/underdeveloped cerebellum
[ more ] |
0007360 |
0000007 | ||
Bile duct proliferation | 0001408 | |
Calcific stippling | 0002832 | |
Cerebral dysmyelination | 0007266 | |
Cholestasis |
Slowed or blocked flow of bile from liver
|
0001396 |
0007371 | ||
Cortical dysplasia | 0002539 | |
Decreased muscle mass | 0003199 | |
Delayed cranial suture closure | 0000270 | |
Delayed skeletal maturation |
Delayed bone maturation
Delayed skeletal development
[ more ] |
0002750 |
Depressed nasal bridge |
Depressed bridge of nose
Flat bridge of nose
Flat nasal bridge
Flat, nasal bridge
Flattened nasal bridge
Low nasal bridge
Low nasal root
[ more ] |
0005280 |
Dolichocephaly |
Long, narrow head
Tall and narrow skull
[ more ] |
0000268 |
Elevated hepatic transaminase |
High liver enzymes
|
0002910 |
Epicanthus |
Eye folds
Prominent eye folds
[ more ] |
0000286 |
Failure to thrive |
Faltering weight
Weight faltering
[ more ] |
0001508 |
Feeding difficulties in infancy | 0008872 | |
Fetal ascites | 0001791 | |
Frontal bossing | 0002007 | |
Generalized cerebral atrophy/hypoplasia |
Generalized cerebral degeneration/underdevelopment
|
0007058 |
Gliosis | 0002171 | |
Global |
0001263 | |
Hammertoe |
Hammer toe
Hammertoes
[ more ] |
0001765 |
Hepatic steatosis |
Fatty infiltration of liver
Fatty liver
[ more ] |
0001397 |
Hepatomegaly |
Enlarged liver
|
0002240 |
High forehead | 0000348 | |
High palate |
Elevated palate
Increased palatal height
[ more ] |
0000218 |
Hypertelorism |
Wide-set eyes
Widely spaced eyes
[ more ] |
0000316 |
Hypoplasia of the corpus callosum |
Underdevelopment of part of brain called corpus callosum
|
0002079 |
Infantile onset |
Onset in first year of life
Onset in infancy
[ more ] |
0003593 |
Large fontanelles |
Wide fontanelles
|
0000239 |
Long philtrum | 0000343 | |
Low-set ears |
Low set ears
Lowset ears
[ more ] |
0000369 |
Macrocephaly |
Increased size of skull
Large head
Large head circumference
[ more ] |
0000256 |
Little lower jaw
Small jaw
Small lower jaw
[ more ] |
0000347 | |
Neonatal hypotonia |
Low muscle tone, in neonatal onset
|
0001319 |
Nystagmus |
Involuntary, rapid, rhythmic eye movements
|
0000639 |
Osteopenia | 0000938 | |
Pectus excavatum |
Funnel chest
|
0000767 |
Polyhydramnios |
High levels of amniotic fluid
|
0001561 |
Polymicrogyria |
More grooves in brain
|
0002126 |
Primary adrenal insufficiency | 0008207 | |
Renal cyst |
Kidney cyst
|
0000107 |
Retrognathia |
Receding chin
Receding lower jaw
Weak chin
Weak jaw
[ more ] |
0000278 |
Scaphocephaly | 0030799 | |
Seizure | 0001250 | |
Split hand |
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities
Split-hand
[ more ] |
0001171 |
Strabismus |
Cross-eyed
Squint
Squint eyes
[ more ] |
0000486 |
Talipes equinovarus |
Club feet
Club foot
Clubfeet
Clubfoot
[ more ] |
0001762 |
Thoracic hypoplasia |
Small chest
Small thorax
[ more ] |
0005257 |
Undetectable electroretinogram | 0000550 | |
Upslanted palpebral fissure |
Upward slanting of the opening between the eyelids
|
0000582 |
Ventriculomegaly |
Cause DBP deficiency is caused by
Mutations in the HSD17B4 gene that cause D-bifunctional protein deficiency can affect one or both of the protein's functions. Although this does not seem to affect the severity of the symptoms of the disorder, the condition may be grouped into three types based on which enzyme(s) is/are deficient:[1][2]
Impairment of one or both of the protein's functions prevents the ability of the protein from breaking down fatty acids properly, resulting in a buildup of fatty acids in the body. It is not clear how the fatty acid buildup leads to the symptoms of this disorder.[1] Diagnosis DBP deficiency can be diagnosed based on lab results showing increased levels of the following: (1) very long-chain fatty acids; (2) α-methyl-branched fatty acids such as pristanic acid and its precursor phytanic acid; and (3) Bile acid intermediates dihydroxycholestanoic acid (DHCA) and trihydroxycholestanoic acid (THCA).
Testing Resources
OrganizationsSupport and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD. Organizations Supporting this Disease
Organizations Providing General Support
Learn moreThese 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. Where to Start
In-Depth Information
References
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