PHARC syndrome is a rare neurodegenerative disorder caused by mutations in the ABHD12 gene. It is a genetically heterogeneous and clinically variable disease, which is characterized by demyelinating polyneuropathy, hearing loss, cerebellar ataxia, retinitis pigmentosa, and early‐onset cataract and can easily be misdiagnosed as other neurologic disorders with a similar clinical picture, such as Charcot‐Marie‐Tooth disease and Refsum disease. We describe the genotype‐phenotype correlation of two siblings with a novel genotype underlying PHARC syndrome. The genotype was identified using next‐generation sequencing. We examined both patients by means of thorough history taking and clinical examination, nerve conduction studies (NCS), brain imaging, and optical coherence tomography to establish a genotype‐phenotype correlation. We identified a novel homozygous point mutation (c.784C > T, p.Arg262*) in the ABHD12 gene. This mutation was detected in both siblings, who had bilateral hearing loss and cataracts, signs of cerebellar ataxia, and neuropathy with a primarily demyelinating pattern in NCS. In one case, retinitis pigmentosa was also evident. As PHARC syndrome is a rare autosomal recessive disorder, our findings highlight the importance of an interdisciplinary diagnostic workup with clinical and molecular genetic testing to avoid a misdiagnosis as Charcot‐Marie‐Tooth disease or Refsum disease.

Introduction: Mutation analysis of inherited monogenic diseases is an important aspect of preimplantation genetic diagnosis. Familial adenomatous polyposis of the colon is an autosomal dominant inherited disorder caused by mutations in the tumor suppressor gene adenomatous polyposis coli (APC). A characteristic of this severe disease is the development of thousands of polyps in the colon which untreated evolve into malignant colon carcinomas. Here we present a novel approach for the establishment of mutation detection in the APC gene in single cells applicable for preimplantation genetic diagnosis. Methods: Single fixed lymphocytes were isolated via laser microdissection and transferred to reaction centers of planar chemically structured glass slides via a recently developed horizontal low-pressure single particle adsorbing transfer system (SPATS). A multiplex nested polymerase chain reaction protocol in a 1-μl reaction volume, followed by sequencing and fragment length analysis was applied in order to detect mutations in the APC gene. Results: Reliable isolation and transfer of single lymphocytes was demonstrated. High amplification efficiency and low allelic drop out (ADO) rates for polymorphic microsatellite markers and mutation specific amplification products of various mutations in the APC gene were obtained from fixed single cells. Conclusions: This novel nanotechnological downscaling approach enables a reliable validation of genetic testing using diploid single lymphocytes, and will open a wide range of single cell diagnostics.

Objective: To demonstrate that a PGD program can be successfully established after the 2011 verdict of the German Bundestag concerning PGD. Material and Method: Eight years previously, the couple had had a daughter who suffered from clinically manifest hemophilia A due to an unbalanced X-inactivation, as well as microdeletion syndrome resulting in severe physical and mental disability. The couple wished to have a second child but refused the idea of a "trial" pregnancy. Given the indications for both, it was necessary to carry out polar body diagnosis (PBD) to rule out hemophilia A and, during the same cycle, a subsequent PGD on the blastocysts to rule out genetic aberrations. The PBD and PGD (trophectoderm biopsy, TEB) were performed after highdosage ovarian stimulation and ICSI fertilization of the oocytes. A blastocyst was successfully transferred on day 6. Results: The patient conceived immediately. The pregnancy developed normally and the patient gave birth to a girl in the 40th week of pregnancy. Post-natal examinations showed that the baby is free from hemophilia A and is developing normally both physically and mentally. Conclusion: Establishment of a PGD program is now possible after legalization of PGD in Germany. It is possible to apply two investigative techniques in a single treatment cycle if multifactorial diagnosis is required.

Background: Molecular autopsy represents an efficient tool to save the diagnosis in up to one-third of sudden unexplained death (SUD). A defined gene panel is usually used for the examination. Alternatively, it is possible to carry out a comprehensive genetic assessment (Whole Exome Sequencing, WES), which also identifies rare, previously unknown variants. The disadvantage is that a dramatic number of variants must be assessed to identify the causal variant. To improve the evaluation of WES, the Human Phenotype Ontology (HPO) annotation is used internationally for deep phenotyping in the field of rare disease. However, a HPO-based evaluation of WES in SUD has not been described before.Methods: We performed WES in tissue samples from 16 people after SUD. Instead of a fixed gene panel, we defined a set of HPO terms and thus created a flexible “virtual gene panel”, with the advantage, that recently identified genes are automatically associated by HPO terms in the HPO database.Results: We obtained a median value of 68,947 variants per sample. Stringent filtering ended up in a median value of 276 variants per sample. Using the HPO-driven virtual gene panel we developed an algorithm that prioritized 1.4% of the variants. Variant interpretation resulted in eleven potentially causative variants in 16 individuals. Conclusion: Our data introduce an effective diagnostic procedure in molecular autopsy of SUD with a non-specific clinical phenotype.