18q deletion syndrome
Updates to Article Attributes
18q syndrome is a rare chromosomal anomalywhere where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as does their severity. Characteristic features include short stature, mental retardation and hypotonia, facial and distal skeletal abnormalities. Chromosome 18q syndrome appears to result from a spontaneous, sporadic chromosomal error during very early embryonic development.
Clinical presentation
The presence of a syndrome is usually evident at or soon after birth. Although there is significant phenotypic variation, some features are relatively constant and include 1:
- decreased growth
- craniofacial dysmorphism
- midface hypoplasia
- frontal bossing
- "carplike" mouth
- genital hypoplasia
- limb abnormalities
- clubfoot
- syndactyly
- short thumbs
- neurological abnormalities
- developmental delay and mental retardation
- ocular movement disorders
- seizures
- autism
Pathology
Chromosome 18q syndrome appears to result from a spontaneous, sporadic chromosomal error during very early embryonic development.
Radiographic features
MRI Brain
The appearance of the brain on MRI is dominated by abnormal white matter, particularly posteriorly and in the periventricular region. It is characterised by bilateral symmetric deep white matter hyperintensity on T2-weighted images, with associated involvement of the subcortical white matter also frequently encountered 1-2,2. The brainstem and cerebellum are usually spared.
MR spectroscopy (MRS)
MRS demonstrates elevated white matter choline and alpha-glutamate concentrations (resonates at 3.75ppm.75 ppm) 3.
-<p><strong>18q syndrome</strong> is a rare <a href="/articles/chromosomal-anomalies">chromosomal anomaly </a>where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as does their severity. Characteristic features include short stature, mental retardation and hypotonia, facial and distal skeletal abnormalities. Chromosome 18q syndrome appears to result from a spontaneous, sporadic chromosomal error during very early embryonic development.</p><h4>Clinical presentation</h4><p>The presence of a syndrome is usually evident at or soon after birth. Although there is significant phenotypic variation, some features are relatively constant and include <sup>1</sup>:</p><ul>- +<p><strong>18q syndrome</strong> is a rare <a href="/articles/chromosomal-anomalies">chromosomal anomaly</a> where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as does their severity. Characteristic features include short stature, mental retardation and hypotonia, facial and distal skeletal abnormalities.</p><h4>Clinical presentation</h4><p>The presence of a syndrome is usually evident at or soon after birth. Although there is significant phenotypic variation, some features are relatively constant and include <sup>1</sup>:</p><ul>
-</ul><h4>Radiographic features</h4><h5>MRI Brain</h5><p>The appearance of the brain on MRI is dominated by abnormal white matter, particularly posteriorly and in the periventricular region. It is characterised by bilateral symmetric deep white matter hyperintensity on T2-weighted images, with associated involvement of the subcortical white matter also frequently encountered <sup>1-2</sup>. The brainstem and cerebellum are usually spared.</p><h6>MR spectroscopy (MRS)</h6><p>MRS demonstrates elevated white matter choline and alpha-glutamate concentrations (resonates at 3.75ppm) <sup>3</sup>. </p>- +</ul><h4>Pathology</h4><p>Chromosome 18q syndrome appears to result from a spontaneous, sporadic chromosomal error during very early embryonic development.</p><h4>Radiographic features</h4><h5>MRI</h5><p>The appearance of the brain on MRI is dominated by abnormal white matter, particularly posteriorly and in the periventricular region. It is characterised by bilateral symmetric deep white matter hyperintensity on T2-weighted images, with associated involvement of the subcortical white matter also frequently encountered <sup>1,2</sup>. The brainstem and cerebellum are usually spared.</p><h6>MR spectroscopy</h6><p>MRS demonstrates elevated white matter choline and alpha-glutamate concentrations (resonates at 3.75 ppm) <sup>3</sup>. </p>
References changed:
- 4. Linnankivi T, Autti T, Pihko S et al. 18q? Syndrome: Brain MRI shows poor differentiation of gray and white matter on T2-weighted images. J. Magn. Reson. Imaging. 2003;18(4):414-419. <a href="https://doi.org/10.1002/jmri.10383">doi:10.1002/jmri.10383</a>
- 5. Kumada T, Ito M, Miyajima T, Fujii T, Okuno T, Kumakura A. [Intractable epilepsy (apneic seizure) in an infant with 18q deletion syndrome]. No To Hattatsu. 2003;35(6):521-6. <a href="https://www.ncbi.nlm.nih.gov/pubmed/14631750">PMID 14631750</a>
- 4.Linnankivi TT, Autti TH, Pihko SH et-al. 18q-syndrome: brain MRI shows poor differentiation of gray and white matter on T2-weighted images. J Magn Reson Imaging. 2003;18 (4): 414-9. <a href="http://dx.doi.org/10.1002/jmri.10383">doi:10.1002/jmri.10383</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/14508777">Pubmed citation</a><span class="auto"></span>
- 5.Kumada T, Ito M, Miyajima T et-al. Intractable epilepsy (apneic seizure) in an infant with 18q deletion syndrome. No To Hattatsu. 2004;35 (6): 521-6. <a href="http://www.ncbi.nlm.nih.gov/pubmed/14631750">Pubmed citation</a><span class="auto"></span>