2024 ICD-10-CM Diagnosis Code G71.13

Myotonic chondrodystrophy

ICD-10-CM Code:
ICD-10 Code for:
Myotonic chondrodystrophy
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Code Navigator:

Code Classification

  • Diseases of the nervous system
    • Diseases of myoneural junction and muscle
      • Primary disorders of muscles

G71.13 is a billable diagnosis code used to specify a medical diagnosis of myotonic chondrodystrophy. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Myotonia congenita
  • Schwartz-Jampel syndrome

Clinical Classification

Clinical Information

  • Myotonia Congenita

    inherited myotonic disorders with early childhood onset myotonia. muscular hypertrophy is common and myotonia may impair ambulation and other movements. it is classified as thomsen (autosomal dominant) or becker (autosomal recessive) generalized myotonia mainly based on the inheritance pattern. becker type is also clinically more severe. an autosomal dominant variant with milder symptoms and later onset is known as myotonia levior. mutations in the voltage-dependent skeletal muscle chloride channel are associated with the disorders.
  • Myotonia

    prolonged failure of muscle relaxation after contraction. this may occur after voluntary contractions, muscle percussion, or electrical stimulation of the muscle. myotonia is a characteristic feature of myotonic disorders.
  • Myotonia Congenita

    a genetic congenital neuromuscular disorder affecting the skeletal muscles. it is caused by mutations in the chloride channel gene (clcn1 gene). it is characterized by muscle stiffness, hypertrophy, pain, and cramping.
  • Paramyotonia Congenita without Cold Paralysis

    an autosomal dominant inherited non-dystrophic myotonia caused by mutations of the scn4a gene. it is characterized by muscle stiffness, which is increased by exposure to cold but does not change to flaccid paralysis with intense cooling.
  • Paramyotonia Congenita|PMC|Paramyotonia Congenita of von Eulenburg

    an autosomal dominant inherited non-dystrophic myotonia caused by mutations of the scn4a gene, resulting in sodium muscle channelopathy. it is characterized by muscle stiffness, which is increased by exposure to cold or activity, and usually eases when the patient warms up through physical activity.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Chondrodystrophic myotonia
  • Congenital myotonic chondrodystrophy
  • Schwartz-Jampel disease

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert G71.13 to ICD-9-CM

  • ICD-9-CM Code: 359.23 - Myotonic chondrodystrphy

Patient Education

Neuromuscular Disorders

Neuromuscular disorders affect your neuromuscular system. They can cause problems with:

  • The nerves that control your muscles
  • Your muscles
  • Communication between your nerves and muscles

These disorders can cause your muscles to become weak and waste away. You may also have symptoms such as spasms, twitching, and pain.

Examples of neuromuscular disorders include:

  • Amyotrophic lateral sclerosis
  • Muscular dystrophy
  • Myasthenia gravis
  • Spinal muscular atrophy

There can be different causes for these diseases. Many of them are genetic.This means they are inherited (run in families) or are caused by a new mutation in your genes. Some neuromuscular disorders are autoimmune diseases. Sometimes the cause is unknown.

Many neuromuscular diseases have no cure. But treatments may improve symptoms, increase mobility, and lengthen life.

[Learn More in MedlinePlus]

Schwartz-Jampel syndrome

Schwartz-Jampel syndrome is a rare condition characterized by permanent muscle stiffness (myotonia) and bone abnormalities known as chondrodysplasia. The signs and symptoms of this condition become apparent sometime after birth, usually in early childhood. Either muscle stiffness or chondrodysplasia can appear first. The muscle and bone abnormalities worsen in childhood, although most affected individuals have a normal lifespan. The specific features of Schwartz-Jampel syndrome vary widely.

Myotonia involves continuous tensing (contraction) of muscles used for movement (skeletal muscles) throughout the body. This sustained muscle contraction causes stiffness that interferes with eating, sitting, walking, and other movements. Sustained contraction of muscles in the face leads to a fixed, "mask-like" facial expression with narrow eye openings (blepharophimosis) and pursed lips. This facial appearance is very specific to Schwartz-Jampel syndrome. Affected individuals may also be nearsighted and experience abnormal blinking or spasms of the eyelids (blepharospasm).

Chondrodysplasia affects the development of the skeleton, particularly the long bones in the arms and legs and the bones of the hips. These bones are shortened and unusually wide at the ends, so affected individuals have short stature. The long bones may also be abnormally curved (bowed). Other bone abnormalities associated with Schwartz-Jampel syndrome include a protruding chest (pectus carinatum), abnormal curvature of the spine, flattened bones of the spine (platyspondyly), and joint abnormalities called contractures that further restrict movement.

Researchers originally described two types of Schwartz-Jampel syndrome. Type 1 has the signs and symptoms described above, while type 2 has more severe bone abnormalities and other health problems and is usually life-threatening in early infancy. Researchers have since discovered that the condition they thought was Schwartz-Jampel syndrome type 2 is actually part of another disorder, Stüve-Wiedemann syndrome, which is caused by mutations in a different gene. They have recommended that the designation Schwartz-Jampel syndrome type 2 no longer be used.

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.