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Myofibrillar myopathy 7(MFM7)

MedGen UID:
934678
Concept ID:
C4310711
Disease or Syndrome
Synonyms: MFM7; MYOPATHY, MYOFIBRILLAR, 7
 
Gene (location): KY (3q22.2)
 
Monarch Initiative: MONDO:0014922
OMIM®: 617114

Definition

Myofibrillar myopathy-7 (MFM7) is an autosomal recessive muscle disorder characterized by early childhood onset of slowly progressive muscle weakness that primarily affects the lower limbs and is associated with joint contractures (summary by Straussberg et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of myofibrillar myopathy, see MFM1 (601419). [from OMIM]

Clinical features

From HPO
Bowel incontinence
MedGen UID:
41977
Concept ID:
C0015732
Disease or Syndrome
Involuntary fecal soiling in adults and children who have usually already been toilet trained.
Urinary incontinence
MedGen UID:
22579
Concept ID:
C0042024
Finding
Loss of the ability to control the urinary bladder leading to involuntary urination.
Myalgia
MedGen UID:
68541
Concept ID:
C0231528
Sign or Symptom
Pain in muscle.
Nocturnal enuresis
MedGen UID:
124355
Concept ID:
C0270327
Mental or Behavioral Dysfunction
Nocturnal enuresis, or nightly bedwetting in children more than 7 years of age, affects about 10% of 7-year-old children, with a wide range of frequencies between populations. The affliction is often linked to major social maladjustments and occupies considerable time in general medical practice. From the age of 7, there is a spontaneous cure rate of 15% per year, such that few remain affected after the age of 16 years. There are 2 types of nocturnal enuresis: type I, the primary form (PNE), with at least 3 nightly episodes in children older than 7 years, where the child has always had the disorder, and type II, or secondary type, where the child has been dry for at least 6 months but enuresis has recurred (summary by Eiberg et al., 1995). Genetic Heterogeneity of Nocturnal Enuresis ENUR1 has been mapped to chromosome 13q, and ENUR2 has been mapped to chromosome 12q.
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).
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).
Foot dorsiflexor weakness
MedGen UID:
356163
Concept ID:
C1866141
Finding
Weakness of the muscles responsible for dorsiflexion of the foot, that is, of the movement of the toes towards the shin. The foot dorsiflexors include the tibialis anterior, the extensor hallucis longus, the extensor digitorum longus, and the peroneus tertius muscles.
Dysphagia
MedGen UID:
41440
Concept ID:
C0011168
Disease or Syndrome
Difficulty in swallowing.
Atypical behavior
MedGen UID:
535345
Concept ID:
C0233514
Mental or Behavioral Dysfunction
Atypical behavior is an abnormality in a person's actions, which can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will.
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.
Scoliosis
MedGen UID:
11348
Concept ID:
C0036439
Disease or Syndrome
The presence of an abnormal lateral curvature of the spine.
Muscle weakness
MedGen UID:
57735
Concept ID:
C0151786
Finding
Reduced strength of muscles.
Multiple joint contractures
MedGen UID:
57633
Concept ID:
C0158118
Acquired Abnormality
Difficulty walking
MedGen UID:
86319
Concept ID:
C0311394
Finding
Reduced ability to walk (ambulate).
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.
Facial palsy
MedGen UID:
87660
Concept ID:
C0376175
Disease or Syndrome
Facial nerve palsy is a dysfunction of cranial nerve VII (the facial nerve) that results in inability to control facial muscles on the affected side with weakness of the muscles of facial expression and eye closure. This can either be present in unilateral or bilateral form.
Shoulder flexion contracture
MedGen UID:
592333
Concept ID:
C0409336
Acquired Abnormality
Chronic reduction in active and passive mobility of the shoulder joint due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement.
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.
Achilles tendon contracture
MedGen UID:
98052
Concept ID:
C0410264
Anatomical Abnormality
A contracture of the Achilles tendon.
Muscular atrophy
MedGen UID:
892680
Concept ID:
C0541794
Pathologic Function
The presence of skeletal muscular atrophy (which is also known as amyotrophy).
Thoracic kyphosis
MedGen UID:
263148
Concept ID:
C1184919
Finding
Over curvature of the thoracic region, leading to a round back or if sever to a hump.
Lumbar hyperlordosis
MedGen UID:
263149
Concept ID:
C1184923
Finding
An abnormal accentuation of the inward curvature of the spine in the lumbar region.
Increased variability in muscle fiber diameter
MedGen UID:
336019
Concept ID:
C1843700
Finding
An abnormally high degree of muscle fiber size variation. This phenotypic feature can be observed upon muscle biopsy.
Spinal rigidity
MedGen UID:
346721
Concept ID:
C1858025
Finding
Reduced ability to move the vertebral column with a resulting limitation of neck and trunk flexion.
Type 2 muscle fiber predominance
MedGen UID:
478817
Concept ID:
C3277187
Finding
An abnormal predominance of type II muscle fibers (in general, this feature can only be observed on muscle biopsy).
Z-band streaming
MedGen UID:
480908
Concept ID:
C3279278
Finding
Streaming or smearing of the Z band, which is then no longer confined to a narrow zone which bisects the I band. The Z disc may extend across the I band or the entire sarcomere in a zigzag manner. Focal thickening, smudging, and blurring of the Z band takes place concurrently. Myofibrillar disorganization is a frequent but not invariable accompanying change.
Limited hip extension
MedGen UID:
766282
Concept ID:
C3553368
Finding
Limitation of the extension of the hip, i.e., decreased ability to straighten the hip joint and thereby increase the angle between torso and thigh; moving the thigh or top of the pelvis backward.
Nemaline bodies
MedGen UID:
814369
Concept ID:
C3808039
Finding
Nemaline rods are abnormal bodies that can occur in skeletal muscle fibers. The rods can be observed on histological analysis of muscle biopsy tissue or upon electron microscopy, where they appear either as extensions of sarcomeric Z-lines, in random array without obvious attachment to Z-lines (often in areas devoid of sarcomeres) or in large clusters localized at the sarcolemma or intermyofibrillar spaces.
Increased Z-disc width
MedGen UID:
1716989
Concept ID:
C5397994
Finding
Abnormally increased width of the Z-disk of the sarcomere, resulting from splitting or opening of the Z-disc (c.f., Figure 2 of PMID:28732005).
Elevated circulating creatine kinase concentration
MedGen UID:
69128
Concept ID:
C0241005
Finding
An elevation of the level of the enzyme creatine kinase (also known as creatine phosphokinase (CK; EC 2.7.3.2) in the blood. CK levels can be elevated in a number of clinical disorders such as myocardial infarction, rhabdomyolysis, and muscular dystrophy.
Increased circulating lactate dehydrogenase concentration
MedGen UID:
1377250
Concept ID:
C4477095
Finding
An elevated level of the enzyme lactate dehydrogenase in the blood circulation.
Tongue atrophy
MedGen UID:
66828
Concept ID:
C0241423
Finding
Wasting of the tongue.

Recent clinical studies

Etiology

Akaba Y, Takeguchi R, Tanaka R, Makita Y, Kimura T, Yanagi K, Kaname T, Nishino I, Takahashi S
J Clin Neuromuscul Dis 2022 Sep 1;24(1):49-54. doi: 10.1097/CND.0000000000000392. PMID: 36005473
Lv X, Zhao B, Xu L, Jiang W, Dai T, Zhao D, Lin P, Yan C
Neurol Sci 2022 May;43(5):3371-3380. Epub 2021 Nov 28 doi: 10.1007/s10072-021-05783-1. PMID: 34839411
Loarce-Martos J, Lilleker JB, Parker M, McHugh N, Chinoy H
Rheumatology (Oxford) 2021 Jul 1;60(7):3398-3403. doi: 10.1093/rheumatology/keaa801. PMID: 33367878
Carvalho AAS, Lacene E, Brochier G, Labasse C, Madelaine A, Silva VGD, Corazzini R, Papadopoulos K, Behin A, Laforêt P, Stojkovic T, Eymard B, Fardeau M, Romero N
Genet Test Mol Biomarkers 2018 Jun;22(6):374-383. doi: 10.1089/gtmb.2018.0004. PMID: 29924655
Odgerel Z, Sarkozy A, Lee HS, McKenna C, Rankin J, Straub V, Lochmüller H, Paola F, D'Amico A, Bertini E, Bushby K, Goldfarb LG
Neuromuscul Disord 2010 Jul;20(7):438-42. Epub 2010 Jun 3 doi: 10.1016/j.nmd.2010.05.004. PMID: 20605452Free PMC Article

Diagnosis

Lv X, Zhao B, Xu L, Jiang W, Dai T, Zhao D, Lin P, Yan C
Neurol Sci 2022 May;43(5):3371-3380. Epub 2021 Nov 28 doi: 10.1007/s10072-021-05783-1. PMID: 34839411
Schänzer A, Schumann E, Zengeler D, Gulatz L, Maroli G, Ahting U, Sprengel A, Gräf S, Hahn A, Jux C, Acker T, Fürst DO, Rupp S, Schuld J, van der Ven PFM
J Muscle Res Cell Motil 2021 Jun;42(2):381-397. Epub 2021 Mar 12 doi: 10.1007/s10974-021-09601-1. PMID: 33710525
Loarce-Martos J, Lilleker JB, Parker M, McHugh N, Chinoy H
Rheumatology (Oxford) 2021 Jul 1;60(7):3398-3403. doi: 10.1093/rheumatology/keaa801. PMID: 33367878
Alhammad RM, Naddaf E
Neuromuscul Disord 2020 Feb;30(2):128-136. Epub 2019 Dec 12 doi: 10.1016/j.nmd.2019.12.001. PMID: 32005492
Carvalho AAS, Lacene E, Brochier G, Labasse C, Madelaine A, Silva VGD, Corazzini R, Papadopoulos K, Behin A, Laforêt P, Stojkovic T, Eymard B, Fardeau M, Romero N
Genet Test Mol Biomarkers 2018 Jun;22(6):374-383. doi: 10.1089/gtmb.2018.0004. PMID: 29924655

Therapy

Loarce-Martos J, Lilleker JB, Parker M, McHugh N, Chinoy H
Rheumatology (Oxford) 2021 Jul 1;60(7):3398-3403. doi: 10.1093/rheumatology/keaa801. PMID: 33367878

Prognosis

Alhammad RM, Naddaf E
Neuromuscul Disord 2020 Feb;30(2):128-136. Epub 2019 Dec 12 doi: 10.1016/j.nmd.2019.12.001. PMID: 32005492
Ma K, Luo D, Tian T, Li N, He X, Rao C, Zhong B, Lu X
Mol Genet Genomic Med 2019 Aug;7(8):e825. Epub 2019 Jun 18 doi: 10.1002/mgg3.825. PMID: 31215171Free PMC Article
Riley LG, Waddell LB, Ghaoui R, Evesson FJ, Cummings BB, Bryen SJ, Joshi H, Wang MX, Brammah S, Kritharides L, Corbett A, MacArthur DG, Cooper ST
Eur J Hum Genet 2019 Aug;27(8):1267-1273. Epub 2019 Apr 25 doi: 10.1038/s41431-019-0393-6. PMID: 31024060Free PMC Article
Jain P, Rajeshwari SM, Singh J, Kumar T, Agarwal SP, Das P
Fetal Pediatr Pathol 2016;35(2):124-8. Epub 2016 Jan 30 doi: 10.3109/15513815.2015.1131783. PMID: 26828629

Clinical prediction guides

Hovhannisyan Y, Li Z, Callon D, Suspène R, Batoumeni V, Canette A, Blanc J, Hocini H, Lefebvre C, El-Jahrani N, Kitsara M, L'honoré A, Kordeli E, Fornes P, Concordet JP, Tachdjian G, Rodriguez AM, Vartanian JP, Béhin A, Wahbi K, Joanne P, Agbulut O
Stem Cell Res Ther 2024 Jan 2;15(1):10. doi: 10.1186/s13287-023-03619-7. PMID: 38167524Free PMC Article
Riley LG, Waddell LB, Ghaoui R, Evesson FJ, Cummings BB, Bryen SJ, Joshi H, Wang MX, Brammah S, Kritharides L, Corbett A, MacArthur DG, Cooper ST
Eur J Hum Genet 2019 Aug;27(8):1267-1273. Epub 2019 Apr 25 doi: 10.1038/s41431-019-0393-6. PMID: 31024060Free PMC Article
Kurapati R, McKenna C, Lindqvist J, Williams D, Simon M, LeProust E, Baker J, Cheeseman M, Carroll N, Denny P, Laval S, Lochmüller H, Ochala J, Blanco G
Hum Mol Genet 2012 Apr 15;21(8):1706-24. Epub 2011 Dec 23 doi: 10.1093/hmg/ddr605. PMID: 22199023
Odgerel Z, Sarkozy A, Lee HS, McKenna C, Rankin J, Straub V, Lochmüller H, Paola F, D'Amico A, Bertini E, Bushby K, Goldfarb LG
Neuromuscul Disord 2010 Jul;20(7):438-42. Epub 2010 Jun 3 doi: 10.1016/j.nmd.2010.05.004. PMID: 20605452Free PMC Article

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