Q04.2 - Holoprosencephaly

Approximate Synonyms

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

• Agnathia, holoprosencephaly, situs inversus syndrome
• Alobar holoprosencephaly
• Cebocephaly
• Congenital stenosis of nasal pyriform aperture
• Hartsfield syndrome
• Holoprosencephaly and postaxial polydactyly syndrome
• Holoprosencephaly craniosynostosis syndrome
• Holoprosencephaly sequence
• Holoprosencephaly with caudal dysgenesis syndrome
• Holoprosencephaly with nasal pyriformis aperture
• Kundrat's syndrome
• Lobar holoprosencephaly
• Middle interhemispheric variant of holoprosencephaly
• Morse Rawnsley Sargent syndrome
• Semi-lobar holoprosencephaly

Clinical Information

• Holoprosencephaly-. anterior midline brain, cranial, and facial malformations resulting from the failure of the embryonic prosencephalon to undergo segmentation and cleavage. alobar prosencephaly is the most severe form and features anophthalmia; cyclopia; severe intellectual disability; cleft lip; cleft palate; seizures; and microcephaly. semilobar holoprosencepaly is characterized by hypotelorism, microphthalmia, coloboma, nasal malformations, and variable degrees of intellectual disability. lobar holoprosencephaly is associated with mild (or absent) facial malformations and intellectual abilities that range from mild intellectual disability to normal. holoprosencephaly is associated with chromosome abnormalities.

Present on Admission (POA)

Q04.2 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.

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Patient Education

Brain Malformations

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, abnormally small or large, or not fully developed.

Treatment depends upon the problem. In many cases, treatment only helps with symptoms. It may include antiseizure medicines, shunts to drain fluid from the brain, and physical therapy.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly uneven heads, but parents should watch the shape of their baby's head for possible problems.

NIH: National Institute of Neurological Disorders and Stroke

Craniofacial Abnormalities

Craniofacial is a medical term that relates to the bones of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft lip and palate, are among the most common of all birth defects. Others are very rare. Most of them affect how a person's face or head looks. These conditions may also affect other parts of the body.

Treatment depends on the type of problem. Plastic and reconstructive surgery may help the person's appearance.

Nonsyndromic holoprosencephaly

Nonsyndromic holoprosencephaly is an abnormality of brain development that also affects the head and face. Normally, the brain divides into two halves (hemispheres) during early development. Holoprosencephaly occurs when the brain fails to divide properly into the right and left hemispheres. This condition is called nonsyndromic to distinguish it from other types of holoprosencephaly caused by genetic syndromes, chromosome abnormalities, or substances that cause birth defects (teratogens). The severity of nonsyndromic holoprosencephaly varies widely among affected individuals, even within the same family.

Nonsyndromic holoprosencephaly can be grouped into four types according to the degree of brain division. From most to least severe, the types are known as alobar, semi-lobar, lobar, and middle interhemispheric variant (MIHV). In the most severe forms of nonsyndromic holoprosencephaly, the brain does not divide at all. These affected individuals have one central eye (cyclopia) and a tubular nasal structure (proboscis) located above the eye. Most babies with severe nonsyndromic holoprosencephaly die before birth or soon after. In the less severe forms, the brain is partially divided and the eyes are usually set close together (hypotelorism). The life expectancy of these affected individuals varies depending on the severity of symptoms.

People with nonsyndromic holoprosencephaly often have a small head (microcephaly), although they can develop a buildup of fluid in the brain (hydrocephalus) that causes increased head size (macrocephaly). Other features may include an opening in the roof of the mouth (cleft palate) with or without a split in the upper lip (cleft lip), one central front tooth instead of two (a single maxillary central incisor), and a flat nasal bridge. The eyeballs may be abnormally small (microphthalmia) or absent (anophthalmia).

Some individuals with nonsyndromic holoprosencephaly have a distinctive pattern of facial features, including a narrowing of the head at the temples, outside corners of the eyes that point upward (upslanting palpebral fissures), large ears, a short nose with upturned nostrils, and a broad and deep space between the nose and mouth (philtrum). In general, the severity of facial features is directly related to the severity of the brain abnormalities. However, individuals with mildly affected facial features can have severe brain abnormalities. Some people do not have apparent structural brain abnormalities but have some of the facial features associated with this condition. These individuals are considered to have a form of the disorder known as microform holoprosencephaly and are typically identified after the birth of a severely affected family member.

Most people with nonsyndromic holoprosencephaly have developmental delay and intellectual disability. Affected individuals also frequently have a malfunctioning pituitary gland, which is a gland located at the base of the brain that produces several hormones. Because pituitary dysfunction leads to the partial or complete absence of these hormones, it can cause a variety of disorders. Most commonly, people with nonsyndromic holoprosencephaly and pituitary dysfunction develop diabetes insipidus, a condition that disrupts the balance between fluid intake and urine excretion. Dysfunction in other parts of the brain can cause seizures, feeding difficulties, and problems regulating body temperature, heart rate, and breathing. The sense of smell may be diminished (hyposmia) or completely absent (anosmia) if the part of the brain that processes smells is underdeveloped or missing.

Code History

• 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 (First year ICD-10-CM implemented into the HIPAA code set)