What is the most likely underlying diagnosis for an 18-hour-old boy with hypotonia, poor suck reflex, and characteristic physical features, including upslanting palpebral fissures and a protruding tongue, born at approximately 40 weeks gestation to a mother with no prenatal care?

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Differential Diagnosis

The patient's presentation of low muscle tone, weak suck, and characteristic physical features suggests a genetic or congenital condition. The following differential diagnosis is organized into categories:

  • Single most likely diagnosis
    • Prader-Willi syndrome: This condition is characterized by hypotonia, poor feeding, and weak suck in infancy, which matches the patient's presentation. The physical features, such as upslanting palpebral fissures and a protruding tongue, are also consistent with Prader-Willi syndrome.
  • Other Likely diagnoses
    • Down syndrome: Although Down syndrome can present with hypotonia and feeding difficulties, the patient's physical features, such as upslanting palpebral fissures and a narrow palate, are more characteristic of Prader-Willi syndrome. However, Down syndrome remains a possible diagnosis.
  • Do Not Miss
    • Infantile botulism: This condition can cause hypotonia, weak suck, and poor feeding, and can be life-threatening if not promptly diagnosed and treated. Although less likely than Prader-Willi syndrome, infantile botulism is a critical diagnosis to consider.
    • Congenital infections or metabolic disorders: Conditions such as congenital hypothyroidism, congenital adrenal hyperplasia, or infections like congenital syphilis or toxoplasmosis can present with hypotonia and feeding difficulties. These diagnoses are less likely but would be critical to identify due to their potential for severe consequences if left untreated.
  • Rare diagnoses
    • Fragile X syndrome: This condition can cause hypotonia and developmental delays, but it is less likely to present with the specific physical features and feeding difficulties seen in this patient.
    • Beckwith-Wiedemann syndrome: This condition is characterized by macrosomia, macroglossia, and omphalocele, which are not present in this patient. However, it can cause hypotonia and feeding difficulties, making it a rare but possible diagnosis to consider.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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