Clinical and genetic study of hereditary disorders in families ascertained from Layyah District

Abstract

Hereditary disorders are commonly observed in the Pakistani population, yet their inheritance pattern, etiology, prevalence, phenotypic variation, and risk factors in various subpopulations remain largely unexplored. The current descriptive clinical and epidemiological genetic study was carried out through a door-to-door survey to investigate the mode of inheritance, prevalence-pattern, and phenotypic manifestations of hereditary disorders in the general population of district Layyah (Punjab). Families and subjects with hereditary disorders were ascertained and pedigrees were drawn according to the family history of the disorder. A total of 500 independent families/subjects with various types of congenital and genetic abnormalities were ascertained. Among the major disease categories, neuromuscular disorders were most common (n=134) followed by neurological disorders (n=124), sensorineural defects (n=114), limb disorders (n=57) and visual impairments (n=37). Among the ascertained cases, males had higher presentation (68%, n=339) than females (32%, n=161). Sporadic (56%, n=282) and isolated cases (56%, n=282) representation was higher than familial (44%, n=218) and syndromic cases (44%, n=218), respectively. A high representation (45%) of subjects falls within the range of 9 to 19 years of age, and the majority belonged to low socio-economic category (80%). The highest incidence was observed with birth order of 1 st parity (n=151). In 82% of cases, the malformation segregated in one generation. In this sample, major factor responsible for genetic disorders was consanguineous marriages found to be in 81% of cases (n=404). This study provides useful information about the prevalence of genetic disorders in the study area and can be potentially helpful for further analysis. Awareness programs about disorders, counseling and prenatal diagnosis can minimize the disease risks.