Brief Summary: The objective is to develop and test, through an iterative process, an intervention to address and support the development of infants with a confirmed diagnosis of a neurogenetic disorder with associated developmental delays or intellectual and developmental disabilities. The proposed project will capitalize and expand upon existing empirically based interventions designed to improve outcomes for infants with suspected developmental delays. Participants will be infants with a confirmed diagnosis of a neurogenetic disorder (e.g., fragile X, Angelman, Prader-Willi, Dup15q, Phelan-McDermid, Rhett, Smith Magenis, Williams, Turner, Kleinfelter, Down syndromes, Duchenne muscular dystrophy) within the first year of life and their parents/caregivers. The intervention, called the Parent and Infant Inter(X)action Intervention (PIXI) is a comprehensive program inclusive of parent education about early infant development and the neurogenetic disorder for which they were diagnosed, direct parent coaching around parent-child interaction, and family/parent well-being support. The protocol includes repeated comprehensive assessments of family and child functioning, along with an examination of feasibility and acceptability of the program.

Detailed Description: The primary goal of the proposed project is to develop and test, through an iterative process, an intervention to address and support the development of infants with a rare neurogenetic condition (e.g., fragile X, Angelman, Prader-Willi, Dup15q, Phelan-McDermid, Rhett, Smith Magenis, Williams, Turner, Kleinfelter, Down syndromes, Duchenne muscular dystrophy) identified prior to emergence of symptoms. PiXI aims to utilize the foundational knowledge available around the development of and early intervention for at-risk infants to both understand the needs of and provide intervention services for families of infants diagnosed pre-symptomatically with rare neurogenetic disorders. The investigators aim to 1) develop PIXI with a pilot sample of families, 2) test the preliminary effects of PIXI on infant and parent outcomes