A 6-week-old infant presents with broad thumbs and broad great toes, postnatal growth deficiency, and distinctive facial features including a beaked nose with the nasal septum extending below the alae nasi, downslanting palpebral fissures, and micrognathia. The infant also has moderate intellectual disability noted on follow-up and a history of feeding difficulties. Genetic testing identifies a pathogenic mutation in CREBBP. Which syndrome does this likely represent?
A 2-month-old female infant presents with an isolated cleft lip and no other abnormalities. Her mother asks whether this represents a malformation, deformation, or disruption. Which description best fits this finding?
A 10-year-old boy with developmental delay and hypotonia is found to have a mosaic karyotype with an isochromosome of the short arm of chromosome 12. Which tissue is most likely to provide diagnostic yield if blood testing is negative?
A 4-year-old child with short stature, pulmonary valve stenosis, and hypertelorism is suspected of having a RAS/MAPK pathway disorder. What is the most likely diagnosis?
A neonate is born with craniosynostosis, midface hypoplasia, and complex syndactyly of the hands and feet. Which gene is most likely mutated?
A 3-year-old with heart defect, hypocalcemia, cleft palate, and learning disability is diagnosed with a microdeletion syndrome. Which region is most likely deleted?
A 10-year-old girl is referred for developmental delay and seizures. She is found to have microcephaly, synophrys, and severe upper limb reduction defects. Which gene is most likely mutated?
A newborn presents with clubfoot, flattened ears, and a history of oligohydramnios. What is the most likely underlying mechanism for this infant’s limb deformity?
A 7-year-old girl with a family history of a rare inherited disorder undergoes linkage analysis for diagnosis. The accuracy of the result is compromised by recombination between the marker and the disease gene. What would most likely decrease the chances of this error?
A 3-year-old boy with Ashkenazi Jewish ancestry presents with hepatosplenomegaly and easy bruising. Family history reveals relatives affected by Gaucher disease and Tay-Sachs disease. What is most likely explanation for increased prevalence of certain autosomal recessive disorders in this population?
