Clinical Guidance

Isolated enlarged parietal foramina caused by a heterozygous ALX4 or MSX2 pathogenic variant are primary osseous defects that are usually asymptomatic. Enlarged parietal foramina/ cranium bifidum may present as an unexpected finding on prenatal ultrasound examination, as a large posterior fontanelle in infancy, or as a coincidental finding on skull radiography in children or adults. To date, at least 100 individuals have been identified with enlarged parietal foramina caused by a heterozygous ALX4 or MSX2 pathogenic variant. Cranium bifidum tends to resolve into distinct enlarged parietal foramina over the first few years of life through the midline ossification of a central bridge of bone bisecting the defect .

Source: GeneReviews — "Enlarged Parietal Foramina"

Differential Diagnosis

Isolated enlarged parietal foramina need to be distinguished from syndromic associations, including those described in . Skeletal dysplasias with consistently broad skull defects and/or wide-open sutures and fontanelles that do not represent or evolve into enlarged parietal foramina, such as classic cleidocranial dysplasia (see Cleidocranial Dysplasia Spectrum Disorder), osteolytic conditions, and metabolic bone disorders, are unlikely to be in the ordinary differential diagnosis scope.

Table 3.

Syndromes with Enlarged Parietal Foramina to Consider in the Differential Diagnosis of Isolated Enlarged Parietal Foramina

Gene/Genetic Mechanism | Disorder | MOI | Clinical Features

Proximal 11p deletion | Potocki-Shaffer syndrome (OMIM 601224) | AD | See .

Source: GeneReviews — "Enlarged Parietal Foramina"

Clinical Guidance

Contact sports should be avoided if a midline bony defect persists.

Source: GeneReviews — "Enlarged Parietal Foramina"

Therapies Under Investigation

Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.

Source: GeneReviews — "Enlarged Parietal Foramina"