- A research team
from Cincinnati Children's Hospital Medical Center and City
University of New York School of Medicine identified a probable
cause of motor development disability
- The loss of
function of 2 genes were found to affect the Bax/Bak signaling pathway
- This results in
the motor development disability among children, even though their
intellectual ability might be average or above average
can affect the quality of life of a patient and a study
conducted by a research team from City University of New York School of
Medicine and Cincinnati Children's Hospital Medical Center, has found a
probable cause. The loss of function of two genes
was found to prevent
the development of motor skills. This study will help in early identification
of the risk for motor development disabilities.
The neural circuits in
the motor cortex region of the brain and the spinal cord were not re-organized
well during maturation when there is a loss of function of the genes.
Genetic Pathway for Motor Development Disabilities
As a part of the study,
the research team bred mice that lacked the molecular signaling of the Bax/Bak
pathway. The study findings showed that
- The Bax/Bak
pathway's downstream molecular targets were essential for the development
of sophisticated connections that existed between the spinal circuits and
identified in the Bax/Bak pathways can be used as markers of developmental
motor disabilities in humans.
Further studies are
required to determine if
- These disruptions
in the Bax/Bak pathways are present among people with skilled motor
- The Bax/Bak
pathway is involved in the regulation of re-organization of other aspects
of the central nervous system of mammals.
Development of Motor
Previous studies have
found that only basic unskilled motor tasks
may be carried out by young
postnatal mammals, which includes human babies. This is because infantile
neural circuitry is activated antagonistically, with muscles opposed to each
other being activated at the same time.
- The neural circuits
between the spinal cord and the brain, re-organize as mammals and humans
begin to grow above infancy
- The neural
connections begin to get more sophisticated
pairs of muscles are activated reciprocally
Children who suffer from
developmental motor disabilities have limited skilled motor abilities. A large
proportion of these people have an immature method of co-activating muscle
pairs into adulthood. This affects their dexterity.
During the process of a
child's development, there could be an impairment or immaturity that occurs in
the organization of movement. There is an immaturity during the processing of
information in the brain. A child diagnosed with dyspraxia is found to have
problems with the way language is perceived.
- Dyspraxia is an
inherited condition, in many instances, and it runs in the family.
- Males are more
likely to be affected than females.
- This condition is
also known as perceptuo motor dysfunction, clumsy child syndrome and motor
- Some of the
characteristic features of this condition include an appearance of being
out of sync, vision problems, writing, posture problem, difficulty with
speaking, reading and writing and poor memory. The
intelligence of people with this disorder is above average or average but
their limb movements are immature.
Connections in Developing Mice
The genetic pathways
that are involved in the circuitry between corticospinal neurons in the motor
cortex and muscles of the mice brain were identified using trans-synaptic viral
and electrophysiological assays. This was used to identify connections that
developed in maturing mice.
‘Gene mutations linked to the Bax/Bak pathway, a pathway that affects neural circuits between the spinal cord and the motor cortex, can lead to motor development disability in children.’
tracing that was used in the current study showed
- The importance of
Bax/Bak signaling in the circuity of the brain of mice that matured.
- That the
development of circuits was also triggered by the Bax/Bak signaling.
- That the opposing
muscle groups were found to be activated reciprocally.
- That the
circuitry that developed in the absence of Bax/Bak signaling restricted
reciprocal activation of these muscles.
Tests to Assess Motor
The mice that were
deficient in the Bax/Bak pathway were subjected to skilled motor tests and it
was found that the animals had
co-activation of opposing flexor muscle pairs and extensor
- Normal reaching
as well as retrieval behaviors when they were given food
- Insufficiency in
- Difficulty with
tests associated with walking on a metal grid and a balance bar, when
measured by foot slips
It is important for
optimum development of
during their early years to ensure healthy transition to
adulthood. Nearly 200 million children across the world do not reach their
developmental potential during the first five years of their life due to poor
health, nutrition, lack of awareness or due to disorders.
According to the World
- Globally, 15-20%
of children have disabilities
- 85% of children with disabilities live in developing
- According to data
from the Census of India (2011)
- 7,862,921 children live with disability in India
- 1,045,656 are affected with movement disorder
Research into causes of
development disorders is necessary to develop preventive strategies or
effective therapy for children with developmental disability. The current study
identified the significance of the Bax/Bak pathway in the development of motor
disabilities; further studies conducted on humans will help in providing better
insights into the complex process of maturation to adulthood.
- What is Dyspraxia? - (http://www.dyslexiaindia.org.in/Dyspraxia.html)