MUSCULAR DYSTROPHIES

NO MORE A RARITY

Abstract

Objectives: Muscular dystrophies are classified into different types based on
their age of onset, clinical severity, rate of progression, distribution of muscles weakness,
pattern of inheritance and the genes involved. As muscular dystrophies are relatively
uncommon disorders, very little work has been done in Pakistan. This study has classified (for
the first time in Pakistan) the patients with different types of muscular dystrophies by clinical
and biochemical correlation. Study Design: Observational, descriptive study. Setting:
Departments of Morbid Anatomy and Histopathology and Human Genetics and Molecular
Biology at University of Health Sciences Lahore. Period: Three years’ (March, 2012-March
2015). Methodology: A total of 100 patients comprising of all age groups and both genders
and with strong clinical suspicion of muscular dystrophy, with or without positive family history,
were included. Detailed clinical history and physical examination findings were recorded
followed by estimation of serum Creatine Phosphokinase (CPK), Lactate Dehyrogenase
(LDH) and Aldolase levels. Results: A total of 77 males (M) and 23 females (F) were included.
Mean age of the patients was 12.1990 + 6.69913 years. Parents of 76 patients reported with
consanguineous marriages while positive family history was reported in 31 patients. Eighty
two cases managed to ambulate with support of other persons while n= 14 patients were
totally non ambulatory. Symmetrical muscle involvement (lower limb followed by upper limb)
was shown by 87 cases (including all males and n=22 females). Involvement of the lower
limbs as a primary weakness followed by symmetrical and severe involvement of the upper
limb girdle and lower limb girdle suggested limb girdle muscle dystrophy (LGMD) in 9 (6F,3M)
patients. Involvement of shoulders and upper limbs as a primary weakness followed by facial
muscles and infrequent involvement of lower limbs suggested fascioscapulohumeral muscle
dystrophy (FSHMD) in 2 cases. Involvement of upper limbs as a primary weakness followed
by lower limbs with a moderate rise in CPK levels and mild phenotype was seen in two female
patient which was quite suggestive of dysferlinopathy. Only two male patients reported onset
of weakness and ambulation loss before 1 year of age that may represent congenital muscle
dystrophy (CMD), dystroglycanopathy or congenital onset of LGMD (cLGMD). Mean serum
CPK, LDH and Aldolase levels were 2376.6364 + 910.78963 U/L, 1030.7800 + 180.1620 U/L
and 10.089 + 1.525 U/L respectively that demonstrated significant association (p<0.05) with
characteristic clinical features. Conclusion: Muscular dystrophies are not only restricted
to dystrophinopathies in our population. Apart from clinical and biochemical parameters,
appropriate histological and/or gene mutation analysis is mandatory for precise classification
of these disorders.