A tall and slim body build with increased arm span to height ratio (>1.05) and a reduced upper-to-lower segment ratio (<0.85), i.e., unusually long arms and legs. The extremities as well as the hands and feet are unusually slim. The phenotype is Disproportionate tall stature (HP_0001519, a Human Phenotype Ontology term). Also known as: Dolichostenomelia, Marfanoid body habitus, Marfanoid habitus, Reduced upper-lower segment ratio.