ALOBAR HOLOPROSENCEPHALY

ALTERNATE NAMES

Holoprosencephaly; HPE; Holoprosencephaly 1 Alobar; Familial Alobar Holoprosencephaly; Holoprosencephaly Sequence

DESCRIPTION

Alobar Holoprosencephaly (HPE) is the most severe type of holoprosencephaly, a structural anomaly of the brain in which there is failed or incomplete separation of the forebrain early in gestation. Alobar HPE occurs when there is a single “monoventricle” and no separation of the cerebral hemispheres.

Children with Alobar HPE often have severe facial anomalies, developmental delays, cognitive limitations, and seizures.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING

Physical findings: Most children with HPE have facial anomalies, including single maxillary central incisor (single tooth), single eye, and cleft lip and palate. Other findings include developmental delay, seizures, hydrocephalus, hypothalamic/pituitary and brain stem dysfunction, abnormal swallow or feeding difficulties, failure to thrive/abnormal growth, and erratic sleep patterns.

ICD-9: 742.2

ONSET AND PROGRESSION

Approximately 50% of children with alobar HPE die before age 4 to 5 months.

TREATMENT

There is no cure for HPE. Treatment is symptomatic and supportive and may include antiepileptic drugs for seizures, hormone replacement therapy for pituitary dysfunction, gastrostomy tube placement, and surgery for cleft lip and palate. EEG and MRI are used to monitor neurologic difficulties and a ventriculo-peritoneal shunt may be placed for hydrocephalus.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for evaluation:

• Clinical history and physical examination that describes the diagnostic features from treating source(s).

• Cranial MRI or CT to document CNS anomalies

Suggested Listings for Evaluation:

DETERMINATION

LISTING

REMARKS

Meets Listing

110.08 A

Medical Equals