Benign Congenital Hypotonia (BCH)

What is benign congenital hypotonia?

Benign congenital hypotonia (BCH) occurs when a child is born with mild muscle weakness that cannot be connected to any other condition. It was first described in 1956. 

What are the symptoms of benign congenital hypotonia?

Children born with BCH are referred to as “floppy babies” at birth. Other symptoms include:

• Flat feet
• Abdominal protrusion
• Inability to walk on the heels
• Accentuation of the spinal cord
• Pes cavus
  • This is a deformity of the foot
• Joint hyperlaxity 
• Myalgia
• Walking on tiptoe
• Muscle contractures
• Developmental delay

What causes benign congenital hypotonia?

Issues in numerous parts of the body can cause BCH, and these have been divided into four sections. The first is problems within the muscles themselves, while the second is issues within the neuromuscular junction (NMJ). The other two are issues with the central nervous system (CNS) and the peripheral nerves. 

How is benign congenital hypotonia diagnosed?

Diagnosis of this condition can be difficult, as hypotonia is often a symptom of other disorders. However, diagnostic criteria have been developed, and they include normal levels of muscle enzymes, normal tendon reflexes, early hypotonia, normal muscle biopsies, active limb movement, normal/mild motor retardation that improves over time, and normal results on ECGs and nerve conduction studies. In most cases, diagnosis depends on ruling out other conditions. Tests to do so include:

• Muscle biopsy
• Karyotyping
• MRI
• CT scan
• Infection screen
• Blood tests
• Nerve conduction studies
• EMG

What are the treatments for benign congenital hypotonia?

There are no approved treatments for BCH; however, physiotherapy has proven to be very helpful for patients. 

Where can I find out more about benign congenital hypotonia?

• Patient
• Healthline
• Muscular Dystrophy Australia