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Background. Dedicator of cytokinesis 2 (DOCK2) deficiency is a rare autosomal recessive combined immunodeficiency presenting with very early onset, severe bacterial and viral infections. In DOCK2 deficiency; T, B and NK cell numbers are decreased and functions are impaired resulting in severe atrophy of secondary lymphoid tissues. The aim of this report is to provide information on clinical and laboratory features and hematopoietic stem cell transplantation (HSCT) outcomes of a DOCK2 deficient patient. The patient was diagnosed by using a targeted next generation sequencing primary immunodeficiency (PID) panel. Lymphocyte subsets were measured by flow-cytometry.Case. Here, we describe a patient with DOCK2 deficiency presented with severe combined immunodeficiency. He underwent HSCT without conditioning regimen before the genetic diagnosis and developed hemophagocytic lymphohistiocytosis(HLH) due to Epstein-Barr virus (EBV) infection.Conclusions. Genetic testing is necessery for early diagnosis of DOCK2 deficiency. The curative treatment should be HSCT soon after diagnosis.

Purpose We aimed to define a novel autosomal recessive neurodevelopmental disorder, characterize its clinical features, and identify the underlying genetic cause for this condition. Methods We performed a detailed clinical characterization of 19 individuals from nine unrelated, consanguineous families with a neurodevelopmental disorder. We used genome/exome sequencing approaches, linkage and cosegregation analyses to identify disease-causing variants, and we performed three-dimensional molecular in silico analysis to predict causality of variants where applicable. Results In all affected individuals who presented with a neurodevelopmental syndrome with progressive microcephaly, seizures, and intellectual disability we identified biallelic disease-causing variants in Protocadherin-gamma-C4 (PCDHGC4). Five variants were predicted to induce premature protein truncation leading to a loss of PCDHGC4 function. The three detected missense variants were located in extracellular cadherin (EC) domains EC5 and EC6 of PCDHGC4, and in silico analysis of the affected residues showed that two of these substitutions were predicted to influence the Ca2+-binding affinity, which is essential for multimerization of the protein, whereas the third missense variant directly influenced the cis-dimerization interface of PCDHGC4. Conclusion We show that biallelic variants in PCDHGC4 are causing a novel autosomal recessive neurodevelopmental disorder and link PCDHGC4 as a member of the clustered PCDH family to a Mendelian disorder in humans.

CD59 regulates the complement activation cascade at the final step by inhibiting formation of membrane attack complex. 1 The lack of CD59 allows uncontrolled complement amplification following spontaneous, viral, or postviral induced complement activation. 2 Inherited CD59 deficiency is a rare autosomal recessive disorder characterized by chronic hemolysis, early-onset recurrent peripheral neuropathy resembling Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy, and together with recurrent strokes. [3][4][5][6] We describe a family with isolated CD59 deficiency with peculiar findings: acute-onset immune-mediated cerebellitis, hemorrhagic longitudinal myelitis, acute disseminated encephalomyelitis (ADEM)-like demyelination in CNS, and subclinical mild chronic neuropathy. This report extends the clinical spectrum of inherited CD59 deficiency syndrome.