2024 ICD-10-CM Diagnosis Code Q77.4

Approximate Synonyms

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

• Acanthosis nigricans
• Achondrogenesis
• Achondrogenesis
• Achondroplasia
• Achondroplasia
• Hypochondroplasia
• Lethal chondrodysplasia with fragmented bone
• Severe achondroplasia, developmental delay, acanthosis nigricans syndrome
• Severe combined immunodeficiency with low T- and B-cell numbers
• Short-limb skeletal dysplasia with severe combined immunodeficiency

Clinical Information

• Achondroplasia

  an autosomal dominant disorder that is the most frequent form of short-limb dwarfism. affected individuals exhibit short stature caused by rhizomelic shortening of the limbs, characteristic facies with frontal bossing and mid-face hypoplasia, exaggerated lumbar lordosis, limitation of elbow extension, genu varum, and trident hand. (online mendelian inheritance in man, http://www.ncbi.nlm.nih.gov/omim, mim#100800, april 20, 2001)

• Acanthosis Nigricans

  a circumscribed melanosis consisting of a brown-pigmented, velvety verrucosity or fine papillomatosis appearing in the axillae and other body folds. it occurs in association with endocrine disorders, underlying malignancy, administration of certain drugs, or as in inherited disorder.

• Achondroplasia

  an autosomal dominant disorder caused by mutation(s) in the fgfr3 gene, encoding fibroblast growth factor receptor 3. the condition is characterized by inappropriate cartilage growth plate differentiation and deficient endochondral growth, manifest clinically with severe rhizomelic short stature, short limbs, characteristic facies with frontal bossing and midface hypoplasia.

• COMP wt Allele|Cartilage Oligomeric Matrix Protein (Pseudoachondroplasia, Epiphyseal Dysplasia 1, Multiple) Gene|Cartilage Oligomeric Matrix Protein wt Allele|Cartilage Oligomeric Matrix Protein(Pseudoachondroplasia, Epiphyseal Dysplasia 1, Multiple) Gene|EDM1|EPD1|MED|PSACH|Pseudoachondroplasia (Epiphyseal Dysplasia 1, Multiple) Gene|THBS5

  human comp wild-type allele is located in the vicinity of 19p13.1 and is approximately 9 kb in length. this allele, which encodes cartilage oligomeric matrix protein, is involved in cartilage structural integrity. mutation of the gene is associated with pseudoachondroplasia and multiple epiphyseal dysplasia 1.

• FGFR3 wt Allele|ACH|Achondroplasia, Thanatophoric Dwarfism Gene|CD333|CEK2|FGFR3|Fibroblast Growth Factor Receptor 3 (Achondroplasia, Thanatophoric Dwarfism) Gene|Fibroblast Growth Factor Receptor 3 wt Allele|HSFGFR3EX|JTK4

  human fgfr3 wild-type allele is located in the vicinity of 4p16.3 and is approximately 15 kb in length. this allele, which encodes fibroblast growth factor receptor 3 protein, is involved in mitogenesis, differentiation, and bone development and maintenance. alterations in the gene resulting in defects cause, achondroplasia, crouzon syndrome, thanatophoric dysplasia, coronal synostosis, hypochondroplasia, bladder and cervix cancers.

• Pseudoachondroplasia

  a rare, autosomal dominant inherited disorder caused by mutations in the comp gene. it is characterized by short stature, short arms and legs, waddling walk, osteoarthritis, and limited range of motion at the elbows and hips.

• Hypochondroplasia

  an autosomal dominant disorder that is often caused by a defect in fibroblast growth factor receptor 3, and characterized by short stature, micromelia, and a comparatively large head. the features are milder than those seen in achondroplasia.

• Achondrogenesis

  a rare group of disorders characterized by defective development of bones and cartilage.

• Type II Achondrogenesis|Achondrogenesis, Type II|Hypochondrogenesis|Langer-Saldino Achondrogenesis

  an autosomal dominant condition caused by mutation(s) in the col2a1 gene, encoding collagen alpha-1(ii) chain. it is the most severe of a spectrum of disorders caused by mutations in the col2a1 gene, characterized by short limbs, small chest and lungs, and abnormal ossification of the spine and pelvis. often, infants die at birth or shortly thereafter.

• Acanthosis Nigricans

  a melanotic cutaneous lesion that develops in the axilla and other body folds. it may be idiopathic, drug-induced, or it may be associated with the presence of an endocrine disorder or malignancy.

• Hyperandrogenism, Insulin Resistance, Acanthosis Nigricans Syndrome|HAIR-AN Syndrome

  a condition characterized by hyperandrogenism, insulin resistance, and acanthosis nigricans, typically associated with obesity in teenage girls. it is considered to be a subtype of polycystic ovarian syndrome, but may occur in male individuals. etiology is unclear, but some cases may be associated with mutations affecting the tyrosine kinase domain of the insulin receptor.

• Insulin Resistant Diabetes Mellitus with Acanthosis Nigricans and Hyperandrogenism|Type A Insulin Resistance Syndrome

  a syndrome of insulin resistance caused by mutation(s) in the insr gene, encoding the insulin receptor. this condition is characterized by a clinical triad of hyperinsulinemia, acanthosis nigricans, and hyperandrogenism without lipodystrophy. this is the least severe of a spectrum of disorders; the other two conditions are rabson-mendenhall syndrome and donohoe syndrome.

Q77.4 is grouped with Diagnostic Related Groups - MS-DRG Mapping

Diagnostic Related Groups (DRGs) are a classification system used to group together diagnosis codes for the purpose of reimbursement and healthcare management. DRGs are used to standardize the way hospitals and other providers are paid for inpatient services. In this system patients are grouped together based on their principal diagnosis in areas referred to as Major Diagnostic Categories (MDC). Once a patient is assigned a particular diagnostic category, providers receive a predetermined payment rate for the services rendered. This reimbursement rate is often fixed and is meant to cover the cost of care for that patient. Reimbursement is also affected by the relative weight of a diagnostic related group based on the severity of a patient's illness and the associated cost of care during hospitalization.

Diagnostic related groups encourage healthcare providers to focus on quality and efficiency in patient care while managing costs effectively. The diagnosis code is present in the following groups for version MS-DRG V41.0 applicable from 10/01/2023 through 09/30/2024.

MS-DRG	MS-DRG Title	MCD	Relative Weight
564	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH MCC	08	1.5619
565	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH CC	08	0.9994
566	OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITHOUT CC/MCC	08	0.7505

The relative weight of a diagnostic related group determines the reimbursement rate based on the severity of a patient's illness and the associated cost of care during hospitalization.

Present on Admission (POA)

Q77.4 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA Indicator	Reason for Code	CMS will pay the CC/MCC DRG?
Y	Diagnosis was present at time of inpatient admission.	YES
N	Diagnosis was not present at time of inpatient admission.	NO
U	Documentation insufficient to determine if the condition was present at the time of inpatient admission.	NO
W	Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.	YES
1	Unreported/Not used - Exempt from POA reporting.	NO

Convert Q77.4 to ICD-9-CM

• ICD-9-CM Code: 756.4 - Chondrodystrophy
  Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education

Dwarfism

People with dwarfism have short stature. This means that their height is under 4' 10" as an adult. They are usually of normal intelligence. Dwarfism most often does happen in families where both parents are of average height.

More than 300 different conditions can cause dwarfism. Achondroplasia is the most common type of dwarfism. Achondroplasia is a genetic condition that affects about 1 in 15,000 to 1 in 40,000 people. It makes your arms and legs short in comparison to your head and trunk. You may also have a larger head and weak muscle tone. Other genetic conditions, kidney disease, and problems with metabolism or hormones can also cause dwarfism.

The conditions that cause dwarfism can also cause other health problems. Most of them are treatable. It is important to have regular checkups throughout your life. With proper medical care, most people with dwarfism have active lives and live as long as other people.

[Learn More in MedlinePlus]

Achondroplasia

Achondroplasia is the most common form of short-limbed dwarfism. The word achondroplasia means "without cartilage formation." Cartilage is a tough but flexible tissue that makes up much of the skeleton during early development. However, in people with achondroplasia the problem is not  forming cartilage but  converting it to bone (a process called ossification), particularly in the long bones of the arms and legs. Achondroplasia is similar to another skeletal disorder called hypochondroplasia, but the features of achondroplasia tend to be more severe.

All people with achondroplasia have short stature. Without treatment, the average height of an adult male with achondroplasia is 131 centimeters (4 feet, 4 inches), and the average height for adult females is 124 centimeters (4 feet, 1 inch). Characteristic features of achondroplasia include an average-size trunk, short arms and legs with particularly short upper arms and thighs, limited range of motion at the elbows, and an enlarged head (macrocephaly) with a prominent forehead. Fingers are typically short and the ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance. 

Health problems commonly associated with achondroplasia include obesity and recurrent ear infections. People with achondroplasia are generally of normal intelligence. In childhood, individuals with the condition usually develop a pronounced and permanent sway of the lower back (lordosis) and bowed legs. Some affected people also develop abnormal front-to-back curvature of the spine (kyphosis) and back pain. 

As affected individuals age, they may experience a potentially serious complication of achondroplasia called spinal stenosis. Spinal stenosis is a narrowing of the spinal canal that can pinch (compress) the upper part of the spinal cord. Spinal stenosis causes with pain, tingling, and weakness in the legs that can make walking difficult. An uncommon but serious complication of achondroplasia in early childhood is stenosis of the hole at the base of the skull where the spinal cord comes out of brain (foramen magnum). This complication can cause compression of the brain stem, which can lead to pauses in breathing during sleep (sleep apnea) or a condition known as hydrocephalus. Hydrocephalus is a buildup of fluid in the brain that can lead to increased head size and related brain abnormalities.

[Learn More in MedlinePlus]

Hypochondroplasia

Hypochondroplasia is a form of short-limbed dwarfism. This condition affects the conversion of cartilage into bone (a process called ossification), particularly in the long bones of the arms and legs. Hypochondroplasia is similar to another skeletal disorder called achondroplasia, but the features tend to be milder.

All people with hypochondroplasia have short stature. The adult height for men with this condition ranges from 138 centimeters to 165 centimeters (4 feet, 6 inches to 5 feet, 5 inches). The height range for adult women is 128 centimeters to 151 centimeters (4 feet, 2 inches to 4 feet, 11 inches).

People with hypochondroplasia have short arms and legs and broad, short hands and feet. Other characteristic features include a a large head (macrocephaly), limited range of motion at the elbows, a sway of the lower back (lordosis), and bowed legs. These signs are generally less pronounced than those seen in people with achondroplasia and may not be noticeable until early or middle childhood. Affected individuals have a small increased risk of a seizure disorder known as temporal lobe epilepsy. Some studies have reported that a small percentage of people with hypochondroplasia have mild to moderate intellectual disability or learning problems, but other studies have produced conflicting results. 

[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.