Final answer:
The infant's symptoms suggest a severe neuromuscular condition, with spinal muscular atrophy as one possible diagnosis. Prognosis can vary, with treatments improving outcomes for some forms of SMA. However, early medical intervention is critical.
Step-by-step explanation:
The description provided suggests that the 3-month-old infant may have a neuromuscular disorder characterized by hypotonia (reduced muscle tone), feeding difficulties, fasciculations of the tongue, absent deep tendon reflexes (DTRs), and a physical position often referred to as 'frog-leg'. Given the severity of these symptoms, one possible diagnosis could be spinal muscular atrophy (SMA), a genetic condition that leads to progressive muscle wasting and weakness. Prognosis varies depending on the type of SMA, with some forms being more severe and potentially fatal, particularly if left untreated. Treatments now available for SMA can improve outcomes, but early intervention is critical. The description of a 'frog-leg' position alongside the other symptoms strengthens the suspicion of a neuromuscular disorder that requires immediate medical attention. Additionally, the symptoms listed align with signs of severe systemic illness, as seen in conditions like neonatal tetanus or bacterial meningitis, which also carry serious prognoses without timely treatment.