RIN2 syndrome, formerly known as macrocephaly, alopecia, cutis laxa and scoliosis (MACS) syndrome, is a very rare inherited connective tissue disorder characterized by macrocephaly, sparse scalp hair, soft-redundant and hyperextensible skin, joint hypermobility, and scoliosis. Patients have progressive facial coarsening with downslanted palpebral fissures, upper eyelid fullness/infraorbital folds, thick/everted vermillion, gingival overgrowth and abnormal position of the teeth. Rarer manifestations such as abnormal high-pitched voice, bronchiectasis, hypergonadotropic hypergonadism and brachydactyly (see this term) have also been reported.

Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border.