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Peroxisome biogenesis disorder 5B(PBD5B)

MedGen UID:
762202
Concept ID:
C3542026
Disease or Syndrome
Synonym: PBD5B
 
Gene (location): PEX2 (8q21.13)
 
Monarch Initiative: MONDO:0013933
OMIM®: 614867

Definition

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 PEX2 gene have cells of complementation group 5 (CG5, equivalent to CG10 and CGF). For information on the history of PBD complementation groups, see 214100. [from OMIM]

Clinical features

From HPO
Pes cavus
MedGen UID:
675590
Concept ID:
C0728829
Congenital Abnormality
An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight).
Decreased liver function
MedGen UID:
65430
Concept ID:
C0232744
Finding
Reduced ability of the liver to perform its functions.
Sensorineural hearing loss disorder
MedGen UID:
9164
Concept ID:
C0018784
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).
Dysarthria
MedGen UID:
8510
Concept ID:
C0013362
Mental or Behavioral Dysfunction
Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.
Tremor
MedGen UID:
21635
Concept ID:
C0040822
Sign or Symptom
An unintentional, oscillating to-and-fro muscle movement about a joint axis.
Unsteady gait
MedGen UID:
68544
Concept ID:
C0231686
Finding
A shaky or wobbly manner of walking.
Dysmetria
MedGen UID:
68583
Concept ID:
C0234162
Finding
A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
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.
Hyporeflexia
MedGen UID:
195967
Concept ID:
C0700078
Finding
Reduction of neurologic reflexes such as the knee-jerk reaction.
Cerebellar atrophy
MedGen UID:
196624
Concept ID:
C0740279
Disease or Syndrome
Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.
Oculomotor apraxia
MedGen UID:
483686
Concept ID:
C3489733
Disease or Syndrome
Ocular motor apraxia is a deficiency in voluntary, horizontal, lateral, fast eye movements (saccades) with retention of slow pursuit movements. The inability to follow objects visually is often compensated by head movements. There may be decreased smooth pursuit, and cancelation of the vestibulo-ocular reflex.
Difficulty running
MedGen UID:
108251
Concept ID:
C0560346
Finding
Reduced ability to run.
Joint hypermobility
MedGen UID:
336793
Concept ID:
C1844820
Finding
The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes.
Generalized hypotonia
MedGen UID:
346841
Concept ID:
C1858120
Finding
Generalized muscular hypotonia (abnormally low muscle tone).
Neonatal hypotonia
MedGen UID:
412209
Concept ID:
C2267233
Disease or Syndrome
Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.
Very long chain fatty acid accumulation
MedGen UID:
481027
Concept ID:
C3279397
Finding
Elevated circulating phytanic acid concentration
MedGen UID:
869360
Concept ID:
C4023786
Finding
An abnormal elevation of phytanic acid.
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.
Retinal dystrophy
MedGen UID:
208903
Concept ID:
C0854723
Finding
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.
Slow saccadic eye movements
MedGen UID:
232942
Concept ID:
C1321329
Finding
An abnormally slow velocity of the saccadic eye movements.
Visual impairment
MedGen UID:
777085
Concept ID:
C3665347
Finding
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.
Rod-cone dystrophy
MedGen UID:
1632921
Concept ID:
C4551714
Disease or Syndrome
An inherited retinal disease subtype in which the rod photoreceptors appear to be more severely affected than the cone photoreceptors. Typical presentation is with nyctalopia (due to rod dysfunction) followed by loss of mid-peripheral field of vision, which gradually extends and leaves many patients with a small central island of vision due to the preservation of macular cones.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVPeroxisome biogenesis disorder 5B

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