Article 4: Classical Mendelian Inheritance and Chromosomal Loci in Familial ALS
Headline: Mendelian Inheritance Patterns and Chromosomal Loci in Familial Amyotrophic Lateral Sclerosis
Introduction: Familial amyotrophic lateral sclerosis follows classic Mendelian segregation patterns, categorizable predominantly into autosomal dominant, autosomal recessive, and X-linked inheritance models. Identifying these distinct chromosomal loci allows clinicians to map phenotypic variations, ranging from adult-onset classic motor neuron disease to juvenile progressive spastic paraplegia.
Major Mendelian Categories:
Autosomal Dominant Loci: Includes ALS1 (SOD1 on 21q22), ALS4 (Senataxin on 9q34), ALS6 (FUS on 16q12), and ALS8 (VAPB on 20q13).
Autosomal Recessive Loci: Includes ALS2 (Alsin on 2q33) and ALS5 (15q15-21), characteristically presenting with juvenile onset and prominent corticospinal signs.
X-Linked Forms: Characterized by male-predominant, early-onset phenotypes mapped to Xp11-q12.