P1 GENETICS Flashcards
Inherited weakness of shoulder girdle muscle
Heterogeneous group of genetically determined disorders is known as
Muscular dystrophy
Causes of MD
- genetic mutations
in blood test of MD you’re checking which enzyme
creatine kinase
incase of Limb-Girdle MD which muscles are involved first
Shoulders & hips
other areas affected in LIMB-GIRDLE MD
heart
Diaphragm / resp. muscles
spine
Etiology / genetic predisposition of limb-girdle MD
- autosomal recessive
- autosomal dominance
onset of LIMB-GIRDLE MD
before middle / late childhood
serum CK levels in LIMB-GIRDLE MD
elevated
EMG & muscle biopsy findings in LIMB-GIRDLE MD
Muscular dystrophy
prognosis of LGMD
Usually need wheelchair by the age of 30
muscles first involved in facioscapulohumeral MD
face , shoulders , upper arms , lower legs
gender affected the most by facioscapulohumeral MD
males more than females
other areas affected in facioscapulohumeral MD
eyes , ears , heart , trunk
Etiology of facioscapulohumeral MD
Autosomal dominance
serum CK levels in facioscapulohumeral MD
greatly elevated
sign of which muscle dystrophy
facioscapulohumeral MD
gender affected with Emery-Dreifuss MD
males
muscles first involved in Emery-Dreifuss MD
upper arms & lower legs
other affected areas in Emery-Dreifuss MD
heart , spine
Etiology of Emery-Dreifuss MD
X- linked recessive
autosomal dominance
onset of Emery-Dreifuss MD
5 -15 years of age
serum CK levels in Emery-Dreifuss MD
Mildly elevated
muscles first involved in oculopharyngeal MD
face ( around the eyes )
neck
upper arms & legs
other areas affected in oculopharyngeal MD
throat
most common MD
Duchenne
gender affected more with Duchenne MD
MALES
muscle weakness onset in duchenne
before 5 years
muscles first involved in Duchenne MD
upper arms & legs
other areas affected in Duchenne MD
brain , throat , heart , spine
stomach , diaphragm ,stomach
Intestines
Protein that holds actin to the sarcolemma
Dystrophin
mention the 3 Dystrophinopathies
- Duchenne muscular dystrophy / DMD
- Becker muscular dystrophy / BMD
- DMD associated dilated cardiomyopathy
Etiology of Dystrophinopathies
X-linked recessive
new mutations
Most mutations in Dystrophinopathies
deletions of exons 46-51
Quantity of dystrophin in DMD
Absent / severely reduced
serum CK levels in DMD
Consistently elevated
age of onset of BMD
12 years
main presenting feature of BMD
Cardiomyopathy
Becker MD commonly affects which gender
males
