BackgroundHeterozygous loss of function mutations within the Filamin A gene in Xq28 are the most frequent cause of bilateral neuronal periventricular nodular heterotopia (PVNH). Most affected females are reported to initially present with difficult to treat seizures at variable age of onset. Psychomotor development and cognition may be normal or mildly to moderately impaired. Distinct associated extracerebral findings have been observed and may help to establish the diagnosis including patent ductus arteriosus Botalli, progressive dystrophic cardiac valve disease and aortic dissection, chronic obstructive lung disease or chronic constipation. Genotype-phenotype correlations could not yet be established.MethodsSanger sequencing and MLPA was performed for a large cohort of 47 patients with Filamin A associated PVNH (age range 1 to 65 years). For 34 patients more detailed clinical information was available from a structured questionnaire and medical charts on family history, development, epileptologic findings, neurological examination, cognition and associated clinical findings. Available detailed cerebral MR imaging was assessed for 20 patients.ResultsThirty-nine different FLNA mutations were observed, they are mainly truncating (37/39) and distributed throughout the entire coding region. No obvious correlation between the number and extend of PVNH and the severity of the individual clinical manifestation was observed. 10 of the mutation carriers so far are without seizures at a median age of 19.7 years. 22 of 24 patients with available educational data were able to attend regular school and obtain professional education according to age.ConclusionsWe report the clinical and mutation spectrum as well as MR imaging for a large cohort of 47 patients with Filamin A associated PVNH including two adult males. Our data are reassuring in regard to psychomotor and cognitive development, which is within normal range for the majority of patients. However, a concerning median diagnostic latency of 17 to 20 years was noted between seizure onset and the genetic diagnosis, intensely delaying appropriate medical surveillance for potentially life threatening cardiovascular complications as well as genetic risk assessment and counseling prior to family planning for this X-linked dominant inherited disorder with high perinatal lethality in hemizygous males.

IL1RAPL1 (interleukin-1 receptor accessory protein-like 1) located at Xp21.3-22.1 has repeatedly been shown to be deleted in patients with a contiguous gene syndrome also affecting neighboring genes, in particular DMD (dystrophin), DAX-1 (NR0B1, nuclear receptor subfamily 0, group B, member 1), and GK (glycerol kinase). In contrast, intragenic deletions of IL1RAPL1 or other mutations or cytogenetic aberrations affecting IL1RAPL1 have only rarely been identified. Up to date, they have mostly been associated with nonspecific mental retardation (MRX). We report on two nonrelated patients with MR and additional dysmorphic features who both show intragenic deletions of IL1RAPL1, one of them being de novo (exon 2) and the other one being inherited from his mother (exons 3-5). Deletions were identified by microarray-based chromosome analysis and confirmed by multiplex PCR and FISH, respectively. These data, along with recent functional studies indicating its role in neuronal development, provide further evidence for the relevance of IL1RAPL1 in the pathogenesis of X-linked MR and add knowledge to the phenotypic spectrum of IL1RAPL1 mutations.

Objective: Amniocentesis, chorionic villi sampling and first trimester combined testing are able to screen for common trisomies 13, 18, and 21 and other atypical chromosomal anomalies (ACA). The most frequent atypical aberrations reported are rare autosomal aneuploidies (RAA) and copy number variations (CNV), which are deletions or duplications of various sizes. We evaluated the clinical outcome of non-invasive prenatal testing (NIPT) results positive for RAA and large CNVs to determine the clinical significance of these abnormal results. Methods: Genome-wide NIPT was performed on 3664 eligible patient samples at a single genetics center. For patients with positive NIPT reports, the prescribing physician was asked retrospectively to provide clinical follow-up information using a standardized questionnaire. Results: RAAs and CNVs (>7 Mb) were detected in 0.5%, and 0.2% of tested cases, respectively. Follow up on pregnancies with an NIPT-positive result for RAA revealed signs of placental insufficiency or intra-uterine death in 50% of the cases and normal outcome at the time of birth in the other 50% of cases. We showed that CNV testing by NIPT allows for the detection of unbalanced translocations and relevant maternal health conditions. Conclusion: NIPT for aneuploidies of all autosomes and large CNVs of at least 7 Mb has a low “non-reportable”-rate (<0.2%) and allows the detection of additional conditions of clinical significance.

Background-Treatment of IgE-mediated food allergy with standard protein-based allergen immunotherapy has proven both unsuccessful and hazardous. Allergen gene vaccination represents a promising alternate, but difficulties in gene targeting and expression in antigen presenting cells represent a major limitation for efficient gene vaccination.