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Arthrogryposis multiplex congenita 1, neurogenic, with myelin defect(AMCNMY; AMC1)

MedGen UID:
1373185
Concept ID:
C4479539
Disease or Syndrome
Synonym: Arthrogryposis multiplex congenita, neurogenic, with myelin defect
 
Gene (location): LGI4 (19q13.12)
 
Monarch Initiative: MONDO:0060486
OMIM®: 617468

Definition

AMC1 is an autosomal recessive severe neurologic disorder with onset in utero. Most affected individuals die in utero or are subject to pregnancy termination because of lack of fetal movements and prenatal evidence of contractures of virtually all joints. Those who survive have generalized contractures and hypotonia. The disorder is caused by a neurogenic defect and poor or absent myelin formation around peripheral nerves rather than by a muscular defect (summary by Xue et al., 2017). <Genetic Heterogeneity of Arthrogryposis Multiplex Congenita Also see AMC2 (208100), caused by mutation in the ERGIC1 gene (617946); AMC3 (618484), caused by mutation in the SYNE1 gene (608441); AMC4 (618776), caused by mutation in the SCYL2 gene (616365); AMC5 (618947), caused by mutation in the TOR1A gene (605204), AMC6 (619334), caused by mutation in the NEB gene (161650), and AMC7 (301127), caused by mutation in the THOC2 gene (300395). [from OMIM]

Clinical features

From HPO
Clubfoot
MedGen UID:
3130
Concept ID:
C0009081
Congenital Abnormality
Clubfoot is a congenital limb deformity defined as fixation of the foot in cavus, adductus, varus, and equinus (i.e., inclined inwards, axially rotated outwards, and pointing downwards) with concomitant soft tissue abnormalities (Cardy et al., 2007). Clubfoot may occur in isolation or as part of a syndrome (e.g., diastrophic dysplasia, 222600). Clubfoot has been reported with deficiency of long bones and mirror-image polydactyly (Gurnett et al., 2008; Klopocki et al., 2012).
Scapular winging
MedGen UID:
66822
Concept ID:
C0240953
Anatomical Abnormality
Abnormal protrusion of the scapula away from the surface of the back.
Knee flexion contracture
MedGen UID:
98042
Concept ID:
C0409355
Finding
A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.
Ankle flexion contracture
MedGen UID:
332440
Concept ID:
C1837407
Anatomical Abnormality
Protruding ear
MedGen UID:
343309
Concept ID:
C1855285
Finding
Angle formed by the plane of the ear and the mastoid bone greater than the 97th centile for age (objective); or, outer edge of the helix more than 2 cm from the mastoid at the point of maximum distance (objective).
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
Focal impaired awareness seizure
MedGen UID:
543022
Concept ID:
C0270834
Disease or Syndrome
Focal impaired awareness seizure (or focal seizure with impaired or lost awareness) is a type of focal-onset seizure characterized by some degree (which may be partial) of impairment of the person's awareness of themselves or their surroundings at any point during the seizure.
Bilateral tonic-clonic seizure
MedGen UID:
141670
Concept ID:
C0494475
Sign or Symptom
A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase.
Micrognathia
MedGen UID:
44428
Concept ID:
C0025990
Congenital Abnormality
Developmental hypoplasia of the mandible.
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Retrognathia
MedGen UID:
19766
Concept ID:
C0035353
Congenital Abnormality
An abnormality in which the mandible is mislocalised posteriorly.
Distal arthrogryposis
MedGen UID:
120512
Concept ID:
C0265213
Disease or Syndrome
An inherited primary limb malformation disorder characterized by congenital contractures of two or more different body areas and without primary neurologic and/or muscle disease that affects limb function.
Flexion contracture
MedGen UID:
83069
Concept ID:
C0333068
Anatomical Abnormality
A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints.
Elbow flexion contracture
MedGen UID:
98367
Concept ID:
C0409338
Acquired Abnormality
An elbow contracture that limits the ability of the elbow joint to be extended (straightened), meaning that the elbow is fixed in an flexed (bent) position.
Hip contracture
MedGen UID:
140815
Concept ID:
C0409354
Acquired Abnormality
Lack of full passive range of motion (restrictions in flexion, extension, or other movements) of the hip joint resulting from structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules and/or skin.
Camptodactyly
MedGen UID:
195780
Concept ID:
C0685409
Congenital Abnormality
The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers or toes cannot be extended to 180 degrees by either active or passive extension.
Poor head control
MedGen UID:
322809
Concept ID:
C1836038
Finding
Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months.
Internally rotated shoulders
MedGen UID:
400062
Concept ID:
C1862491
Finding
Arthrogryposis multiplex congenita
MedGen UID:
1830310
Concept ID:
C5779613
Disease or Syndrome
Multiple congenital contractures in different body areas.
Pulmonary hypoplasia
MedGen UID:
78574
Concept ID:
C0265783
Congenital Abnormality
A congenital abnormality in which the lung parenchyma is not fully developed. It may be associated with other congenital abnormalities.
Dental crowding
MedGen UID:
11850
Concept ID:
C0040433
Finding
Changes in alignment of teeth in the dental arch
High palate
MedGen UID:
66814
Concept ID:
C0240635
Congenital Abnormality
Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).
Narrow forehead
MedGen UID:
326956
Concept ID:
C1839758
Finding
Width of the forehead or distance between the frontotemporales is more than two standard deviations below the mean (objective); or apparently narrow intertemporal region (subjective).
Decreased fetal movement
MedGen UID:
68618
Concept ID:
C0235659
Finding
An abnormal reduction in quantity or strength of fetal movements.
Fetal akinesia deformation sequence 1
MedGen UID:
220903
Concept ID:
C1276035
Disease or Syndrome
Decreased fetal activity associated with multiple joint contractures, facial anomalies and pulmonary hypoplasia. Ultrasound examination may reveal polyhydramnios, ankylosis, scalp edema, and decreased chest movements (reflecting pulmonary hypoplasia).
Ptosis
MedGen UID:
2287
Concept ID:
C0005745
Disease or Syndrome
The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).
Esotropia
MedGen UID:
4550
Concept ID:
C0014877
Disease or Syndrome
A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more.
Strabismus
MedGen UID:
21337
Concept ID:
C0038379
Disease or Syndrome
A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.

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