Arthrogryposis multiplex congenita, distal type 2

Arthrogryposis Multiplex Congenita, Distal Type 2

Arthrogryposis Multiplex Congenita (AMC) refers to a group of congenital conditions characterized by multiple joint contractures found throughout the body at birth. Distal arthrogryposis is a subset of AMC that primarily affects the distal parts of the limbs, such as the hands and feet. Distal Type 2, also known as Freeman-Sheldon syndrome or Whistling Face syndrome, is a specific type of distal arthrogryposis.

Clinical Features

Individuals with Arthrogryposis Multiplex Congenita, Distal Type 2, exhibit a range of distinctive clinical features. These include:

• Facial Characteristics: A small mouth with pursed lips, giving a "whistling face" appearance, a prominent forehead, and a small chin.
• Joint Contractures: Contractures are most commonly seen in the hands and feet, leading to camptodactyly (permanently bent fingers) and clubfoot.
• Muscle Weakness: Generalized muscle weakness is often present, contributing to the joint contractures.
• Skeletal Abnormalities: Scoliosis and other skeletal deformities may be present.
• Ocular Abnormalities: Ptosis (drooping of the upper eyelid) and strabismus (misalignment of the eyes) are common.

Genetics

Arthrogryposis Multiplex Congenita, Distal Type 2, is typically inherited in an autosomal dominant pattern. Mutations in the MYH3 gene, which encodes a protein involved in muscle contraction, have been identified as a cause of this condition. Genetic testing can confirm the diagnosis by identifying mutations in this gene.

Diagnosis

Diagnosis of Distal Type 2 arthrogryposis is based on clinical evaluation and the presence of characteristic physical features. Genetic testing can provide confirmation. Prenatal ultrasound may detect joint contractures, but specific diagnosis is usually made after birth.

Management

Management of Arthrogryposis Multiplex Congenita, Distal Type 2, is multidisciplinary and focuses on improving function and quality of life. Treatment options include:

• Physical Therapy: To improve range of motion and muscle strength.
• Orthopedic Interventions: Surgery may be necessary to correct severe joint contractures or skeletal deformities.
• Speech Therapy: To address difficulties with speech and feeding due to facial abnormalities.
• Genetic Counseling: For affected individuals and their families to understand the inheritance pattern and risks for future pregnancies.

Prognosis

The prognosis for individuals with Arthrogryposis Multiplex Congenita, Distal Type 2, varies depending on the severity of the condition and the effectiveness of interventions. With appropriate management, many individuals can lead productive lives, although they may face challenges related to mobility and physical function.

Also see

• Arthrogryposis Multiplex Congenita
• Distal Arthrogryposis
• Freeman-Sheldon Syndrome
• Congenital Contractures
• Genetic Disorders