A young boy diagnosed with XLA is now on regular immunoglobulin replacement therapy. His parents ask about the implications of this diagnosis for his siblings. What is the inheritance pattern of X-linked Agammaglobulinemia, and what is the risk for the siblings of an affected boy?

A 1-year-old boy presents with a history of recurrent pneumonia and sinus infections. Laboratory findings show very low serum levels of IgG, IgA, and IgM. Flow cytometry shows an absence of CD19+ B cells. Which of the following tests would confirm the diagnosis of X-linked agammaglobulinemia?

A 7-year-old boy with Fragile X syndrome is brought to the clinic for behavioral management. His parents report that he has significant anxiety, hand-flapping, and poor eye contact. They also mention that he has a history of seizures.Which of the following is the most appropriate pharmacological treatment for anxiety in this patient?

A 30-year-old woman presents with primary ovarian insufficiency (POI), characterized by irregular menstrual cycles and infertility. Her brother was diagnosed with Fragile X syndrome in childhood. The physician suspects she may be a carrier of a premutation in the FMR1 gene. What is the most likely number of CGG repeats in the FMR1 gene in this patient?

A 10-year-old boy with Fragile X syndrome is evaluated for behavioral issues. Which of the following is a common behavioral characteristic associated with this condition?

A 5-year-old boy with developmental delay, autism spectrum disorder (ASD), and seizures is diagnosed with Fragile X syndrome after genetic testing confirms >200 CGG repeats in the FMR1 gene. His parents ask about the inheritance pattern and risks for future children. What is the inheritance pattern of Fragile X syndrome, and what key feature affects its transmission?

A 7-year-old girl presents to the genetics clinic with mild intellectual disability, anxiety, and attention deficit hyperactivity disorder (ADHD). Her family history reveals that her maternal uncle has Fragile X syndrome. Genetic testing shows she has 80 CGG repeats in her FMR1 gene. What is the most accurate classification of her FMR1 gene status?

A 7-year-old boy is brought to the pediatrician by his parents due to concerns about developmental delay, hyperactivity, and poor eye contact. The parents report that he has difficulty with speech and social interactions, often avoiding eye contact and displaying repetitive behaviors such as hand-flapping. On physical examination, the child has a long face, large protruding ears, and macroorchidism (enlarged testicles). His family history is notable for a maternal uncle with intellectual disability and similar physical features. Given these findings, which genetic mutation is most likely responsible for his condition?

A 28-year-old woman presents to the emergency department with sudden-onset abdominal pain and hypotension. She has a history of easy bruising, thin translucent skin, and recurrent arterial dissections. Her mother died at age 35 from an aortic rupture. Genetic testing confirms a COL3A1 mutation. Which of the following best describes the underlying defect in this condition?

A 32-year-old female patient presents to the emergency department with sudden-onset abdominal pain and a history of easy bruising since childhood. She reports a family history of unexplained arterial ruptures and has previously been diagnosed with Vascular Ehlers-Danlos Syndrome (vEDS). Genetic testing confirmed a mutation in the COL3A1 gene. Physical examination reveals a thin, translucent skin appearance and hypermobile joints. Given her diagnosis and the molecular basis of vEDS, the medical team considers the underlying pathology to guide management. Based on the molecular pathology of Vascular Ehlers-Danlos Syndrome (vEDS) involving dominant negative mutations in the COL3A1 gene, which of the following best describes the primary consequence in affected tissues?