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Peroxisome biogenesis disorder 7B(PBD7B)

MedGen UID:
Concept ID:
Disease or Syndrome
Synonym: PBD7B
Gene (location): PEX26 (22q11.21)
Monarch Initiative: MONDO:0013939
OMIM®: 614873


The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX26 gene have cells of complementation group 8 (CG8, equivalent to CGA). For information on the history of PBD complementation groups, see 214100. [from OMIM]

Clinical features

From HPO
Decreased liver function
MedGen UID:
Concept ID:
Reduced ability of the liver to perform its functions.
Sensorineural hearing impairment
MedGen UID:
Concept ID:
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Global developmental delay
MedGen UID:
Concept ID:
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Neonatal hypotonia
MedGen UID:
Concept ID:
Disease or Syndrome
Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.
Retinal dystrophy
MedGen UID:
Concept ID:
Retinal dystrophy is an abnormality of the retina associated with a hereditary process. Retinal dystrophies are defined by their predominantly monogenic inheritance and they are frequently associated with loss or dysfunction of photoreceptor cells as a primary or secondary event.
Visual impairment
MedGen UID:
Concept ID:
Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVPeroxisome biogenesis disorder 7B

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