Brachydactyly
The content of the article:
- Causes and risk factors
-
Forms of the disease
- Type A
- Type B
- Type C
- Type D
- Type E
- Symptoms
- Diagnostics
- Treatment
- Forecast
Brachydactyly (short toes) is a congenital pathology, the main manifestation of which is shortening of the toes or hands (from ancient Greek βραχύς - “short” and δάκτυλος - “finger”) due to hypo or aplasia of the distal phalanges or metacarpal bones (metatarsus).
Quite often, short-fingeredness is combined with the fusion of adjacent phalanges of the fingers in the joints or individual fingers together.
In the structure of hereditary pathologies of the hands and feet, brachydactyly accounts for almost a quarter of their total number; the incidence of the disease in the population is 1.5 cases per 100,000 population.
Shortening of the fingers of the hands with brachydactyly
Causes and risk factors
Short-toed is a congenital disease with an autosomal dominant type of inheritance: for the manifestation of the disease in a child, it is enough to have a defective gene in one of the parents.
The most common cause of brachydactyly is the mutation of the following genes: IHH (locus 2q35), CDF5 (20q11.22), BMPR1B (4q22.3), MP2 (20p12.3), Ror2 (9q22.31), STILL (17q22), HOXD13 (2q31.1), PTHLH (12p11.22); in some cases, it is not possible to reliably identify the damaged gene.
In addition to brachydactyly, mutations of these genes can lead to a number of other pathologies of the skeletal system; in this situation, short-fingeredness acts as one of the many symptoms of combined pathology.
Forms of the disease
Depending on the degree of involvement of the bone skeleton in the pathological process, several types of the disease are distinguished.
Type A
Brachymesophalangia - shortening of all fingers due to underdevelopment of the middle phalanges:
- subtype A1 (including A1C, A1B) (Farabi type) - all middle phalanges are rudimentary, sometimes merge with the terminal ones, the proximal phalanges of the I toe and feet are shortened. The brushes are wide, short; the distal interphalangeal fold is absent. Growth retardation sometimes occurs;
- subtype A2 (type Mora - Vrita) - shortening of the middle phalanx of the second toe and foot with relatively intact remaining fingers, clinodactyly of the little finger. Due to the rhomboid or triangular shape of the middle phalanges, II fingers are deflected radially;
- subtype A3 (brachymesophalangia of the V finger) - shortening with a radial curvature of the middle phalanx of the V finger. The rhomboid or triangular shape of the rudimentary middle phalanx determines the development of clinodactyly of the fifth fingers;
- subtype A4 (type Temtami; brachymesophalangia of the II and V fingers) - defeat of the II and V fingers of the hand, the absence of the middle phalanges of the II-V toes, dysplasia of the nails, congenital calcaneal-valgus clubfoot is possible;
- subtype A5 - absence of middle phalanges of II – V fingers with nail dysplasia;
- subtype A6 (Osebold-Remondini syndrome) is characterized by mesomelic shortening of the limbs and damage to the bones of the wrist and tarsus.
Brachymesophalangia of the V finger on an X-ray
Type B
In addition to the shortening of the middle phalanges, characteristic of type A, there are underdevelopment or absence of the distal phalanges of the fingers and toes, fusion of the II and III fingers.
Type C
It is characterized by shortening of the middle and proximal phalanges of the II and III fingers, sometimes with hypersegmentation of the proximal phalanges, symphalangia and shortening of the metacarpal bones are possible, shortening of the thumb due to the underdevelopment of the I metacarpal bone. There are short stature and mental retardation of the patient.
Type D
Brachymegalodactyly - shortening of the thumbs and feet by shortening the distal phalanx.
Forms of brachydactyly
Type E
Shortening of the metacarpal and metatarsal bones.
The most common subtypes A3 and D.
Symptoms
If brachydactyly is an independent disease, its main manifestations are shortening and (in some cases) curvature of the bones of the hands and feet. There are no disruptions in the functioning of other systems and organs; bone deformation is often purely cosmetic in nature, without affecting the quality of life.
In the presence of fusion between adjacent phalanges and disruption of the functioning of the interphalangeal joints, there is a deterioration in the supporting and motor functions, it is difficult to grip and hold small objects, and fine motor skills suffer.
Fusion of fingers in a child
Sometimes short toes are accompanied by underdevelopment or complete absence of nail plates.
In some cases, brachydactyly is one of the many manifestations of gross genetic pathology (Down's disease, Poland's syndrome, Aarskog-Scott disease, etc.), then it is considered as a symptom, and not an independent disease.
Diagnostics
The main diagnostic techniques are an objective examination of the patient and X-ray examination, which allows to determine the degree of damage to the limb bones.
Treatment
Brachydactyly without dysfunction of the hands and feet does not require special treatment.
In the case of limited mobility and functional inconsistency of the limbs, surgical correction is performed, which consists in eliminating interphalangeal adhesions and lengthening the linear dimensions of the corresponding bones. For this purpose, autologous transplantation, pollicisation and distraction are performed with muscle-tendon and skin plastics.
Forecast
The prognosis is favorable, the disease usually does not limit the social and work activity of patients. In the case of functional limitations, surgical intervention allows you to completely eliminate the existing defects.
Olesya Smolnyakova Therapy, clinical pharmacology and pharmacotherapy About the author
Education: higher, 2004 (GOU VPO "Kursk State Medical University"), specialty "General Medicine", qualification "Doctor". 2008-2012 - Postgraduate student of the Department of Clinical Pharmacology, KSMU, Candidate of Medical Sciences (2013, specialty "Pharmacology, Clinical Pharmacology"). 2014-2015 - professional retraining, specialty "Management in education", FSBEI HPE "KSU".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
