Potocki-Lupski syndrome mimicking a connective tissue disorder

We report the case of a 16-year-old boy with 17p11.2 duplication (Potocki-Lupski syndrome, PTLS) and thoracic kyphosis. He was first referred to Clinical Genetics at the age of 21 2 years following a diagnosis of global developmental delay and benign hypotonia. He was noted to be a tall boy (height on the 90th centile and head circumference on the 97th centile) with long toes. He is the second child of non-consanguineous parents. Pregnancy was unremarkable, and he was born at full term by emergency Caesarean section for a brow presentation. He was a large baby with a birth weight of 3.8 kg. He was noted to be floppy and slow to feed soon after birth. At 4 months of age, following normal electromyography and nerve conduction studies, he was diagnosed with benign hypotonia, which later resolved spontaneously. His development was delayed globally. He first walked at 18 months and at the age of 6 years, he was noted to have difficulties with coordination. His first spoken words came only at the age of 6 years. He was a hyperactive child and had episodes of breath holding until the age of 5 years.