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Aicardi Syndrome and Klinefelter Syndrome
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Aicardi syndrome is a rare genetic disease affecting 1 in 100,000 newborn females and occasionally 47,XXY males. Initially characterized by a classical trio of agenesis of the corpus callosum, infantile spasms (seizures/epilepsy), and chorioretinal lacunae, the clinical profile of Aicardi syndrome has been extended to include other neuronal and extraneuronal defects, such as characteristic facial features (prominent premaxilla, upturned nasal tip, decreased angle of the nasal bridge, sparse lateral eyebrows, coloboma of the optic nerve), microcephaly, periventricular heterotopias, microgyria, enlarged ventricles or porencephalic cysts, moderate-to-severe developmental delay and intellectual disability, as well as increased cancer risk (e.g., choroid plexus papilloma, choroid plexus carcinoma, lipoma, angiosarcoma, hepatoblastoma, intestinal polyposis, benign teratoma, embryonal carcinoma, retinoblastoma) [11].
Central nervous system: Paediatric and neurodevelopmental disorders
Published in Angus Clarke, Alex Murray, Julian Sampson, Harper's Practical Genetic Counselling, 2019
This may occur as part of a more general cerebral maldevelopment, or it may be isolated. Most isolated cases have been sporadic, although occasional families following an apparently X-linked recessive pattern have been recorded. Aicardi syndrome is an X-linked dominant disorder associated with infantile spasms and patches of retinal pathology or a failure to develop (retinal lacunae). Its genetic basis remains uncertain, but it is almost always sporadic and affects females. It may be lethal to males in utero or, like Rett syndrome, it may result from mutations at spermatogenesis. Several syndromes with limb defects (acrocallosal, Neu-Laxova) are autosomal recessive.
Choroid Plexus Tumors and Meningiomas
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Kenneth K. Wong, Elwira Szychot, Jennifer A. Cotter, Mark Krieger
CPTs are rare tumors of neuroectodermal origin and are associated with both germline and somatic abnormalities located at several genetic loci. CPC is associated withLi–Fraumeni syndrome (LFS), which is characterized by germline mutations in the TP53 tumor suppressor gene. The TP53 gene normally expresses the protein product p53; a pathogenic mutation of the TP53 gene may cause aberrant p53 function and prolongation of the half-life of the protein. About 40% of CPCs occur in the setting of LFS. Gozali et al. identified an association between TP53 germline mutations and CPC in a 19-year institutional cohort: 6 of 42 CPT patients had phenotypic and/or genotypic characteristics consistent with LFS, i.e., a distinct family history of cancer or a synchronous or metachronous other cancer.27 Of 11 patients with CPC tested for TP53 germline mutations, 4 (36.4%) were positive. In a different multi-institution study of 64 patients with either CPP or CPC, TP53 germline mutations were identified in all CPCs from patients with a clinical diagnosis of LFS.28 In contrast, such germline mutations were absent in all patients with CPPs and non-LFS-associated CPCs. The presence of a TP53 mutation by immunohistochemistry has been associated with worse outcomes.27–30 Aicardi syndrome is a rare, X chromosome-linked dominant condition observed in female patients. Several authors have reported CPPs in girls with Aicardi syndrome.31,32 A CPT has also been associated with von Hippel–Lindau disease.33
Aplasia of the Optic Nerve: A Report of Seven Cases
Published in Neuro-Ophthalmology, 2020
Yujia Zhou, Maura E. Ryan, Marilyn B. Mets, Hawke H. Yoon, Bahram Rahmani, Sudhi P. Kurup
A 2-month-old, full-term girl presented with irregular pupils and asymmetric eyes. Pregnancy was notable for maternal smoking during the second and third trimesters. Bilaterally, there was a glial opacity with abnormal vessels around the rim in the typical location of the optic nerve head. The fundus also displayed scattered, lacunae-like chorioretinal coloboma (Figure 1h). Both eyes were microphthalmic with microcornea with associated haze and thick pachymetry (Figure 1d). On the MRI, there was a small pars intermedia cyst, favoured to be incidental, and a hypoplastic dorsal C1 arch with associated craniovertebral junction stenosis. She underwent posterior fossa decompression at the age of 10 months. Surveillance showed an unchanged pituitary cyst size, and she has had no endocrinologic dysfunction. Aicardi syndrome was ruled out due to the patient’s normal chromosomal microarray and absence of dermatological findings and seizures. Neurologic evaluation noted delays in visual-dependent skills. At the time of this report, the patient was healthy at 5 years old and has had subsequent imaging demonstrating an unremarkable skull base.