Chromosome 1q duplication syndrome. Chromosome 1q plus syndrome. Trisomy 1q.
Incidence
Duplication usually involves about two-thirds of the long arm of chromosome 1. Variable incidence, and clinical symptoms vary of type of duplication.
Clinical Characteristics
Duplication of the long arm of chromosome 1 associated with a variable phenotype, including psychomotor retardation, craniofacial malformations, and various limb, heart, and urogenital anomalies. Duplication usually involves about two-thirds of the long arm of chromosome 1. Duplications 1(q24-qter) and 1q(25-qter) cause the most severe abnormalities and are associated with the shortest life-span, duplication 1q(32-qter) is less severe, and 1q(42-qter) is usually mild with longer survival and near normal intellectual development. Mosaicism for tandem duplication [dup(1)(q12q22)] exhibits mild neonatal asphyxia, hip dislocation, micrognathia, narrow palpebral fissures, pes cavus, short neck, thin fingers, kyphoscoliosis, esophageal incoordination, brain atrophy, and severe psychomotor retardation. Duplication 1q may be associated with additional chromosomal abnormalities resulting from unbalanced translocation.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype shows duplication of the long arm of chromosome 1