P469: Complex mosaicism for up to three marker chromosomes causing partial trisomy for portions of 1p and 10p-10q: A case

Treatment and Management: Our patient required supplemental oxygen, feeding tube placement, and surgical intervention for cardiac anomalies.Outcome and Follow-Up: After 10 weeks in the NICU, the patient was discharged with a feeding tube and supplemental oxygen requirements.Discussion: Gains in the region of 1p13.1-p12 have been associated in the genetics database, DECIPHER, with variable phenotypes, ranging from normal phenotypes to ectopic ossification, microcephaly, trigonocephaly, strabismus, and varying degrees of intellectual disability.The literature reports that individuals with gains in the pericentromeric region of chromosome 10 have mostly normal phenotypes except in one case with oropharyngeal abnormalities.Similar gains within the identified 10p and 10q region have not been described in DECIPHER, but smaller gains within these areas were associated with ventricular septal defects, aortic coarctation, scapulohumeral muscular dystrophy, micrognathia, kidney abnormalities, and varying degrees of intellectual disability.Conclusion: This report highlights the rarity and phenotypic consequences of chromosomes 1p and 10p-10q duplications and the apparent uniqueness of their co-occurrence.Further genetic analysis is warranted to identify the regions correlated with anatomic and developmental characteristics and ultimately guide clinical management for similar cases.Introduction: We present a male neonate with abnormal chromosomal analyses significant for mosaicism involving 3 de novo markers, causing partial trisomy for portions of 1p and 10p-q, and presenting with multiple malformations.There are limited reports in the current literature to establish phenotype-genotype correlations and guide clinical management.Case Presentation: The patient was born by repeat cesarean route at 36 weeks gestation.Pregnancy and delivery were uncomplicated.The neonatal period was notable for multiple malformations and hypotonia.At 48 days of life, the patient had significant malformations including microcephaly (32 cm; < 3rd percentile), depressed metopic suture, hypoplastic pinnae, broad nasal bridge, wide-set, down-slanting palpebral fissures, micrognathia, and a III/VI systolic murmur.Echocardiogram revealed a large ventricular septal defect, a small patent foramen ovale, a patent ductus arteriosus, and a tortuous aorta.Cranial ultrasound showed a hypoplastic corpus callosum.