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ATP6AP1-CDG is an X-linked disorder typically characterized by hepatopathy, immunodeficiency and an abnormal type II transferrin glycosylation pattern. Here, we present eleven new patients and clinical updates with biochemical characterization on one previously reported patient. We also document intrafamilial phenotypic variability and atypical presentations, expanding the symptomatology of ATP6AP1-CDG to include dystonia, hepatocellular carcinoma, and lysosomal abnormalities on hepatic histology. Three of our subjects received successful liver transplantation. We performed N-glycan profiling of total and fractionated plasma proteins for six patients and show associations with varying phenotypes, demonstrating potential diagnostic and prognostic value of fractionated N-glycan profiles. The aberrant N-linked glycosylation in purified transferrin and remaining plasma glycoprotein fractions normalized in one patient post hepatic transplant, while the increases of Man4GlcNAc2 and Man5GlcNAc2 in purified immunoglobulins persisted. Interestingly, in the single patient with isolated immune deficiency phenotype, elevated high-mannose glycans were detected on purified immunoglobulins without glycosylation abnormalities on transferrin or the remaining plasma glycoprotein fractions. Given the diverse and often tissue specific clinical presentations and the need of clinical management post hepatic transplant in ATP6AP1-CDG patients, these results demonstrate that fractionated plasma N-glycan profiling could be a valuable tool in diagnosis and disease monitoring.

We report three unrelated probands, two male and one female, diagnosed with Aicardi-Goutieres syndrome (AGS) after screening positive on California newborn screening (CA NBS) for X-linked adrenoleukodystrophy (X-ALD) due to elevated C26:0 lysophosphatidylcholine (C26:0-LPC). Follow-up evaluation was notable for elevated C26:0, C26:1, and C26:0/C22:0 ratio, and normal red blood cell plasmalogens levels in all three probands. Diagnoses were confirmed by molecular sequencing prior to 12 months of age after clinical evaluation was inconsistent with X-ALD or suggestive of AGS. For at least one proband, the early diagnosis of AGS enabled candidacy for enrollment into a therapeutic clinical trial. This report demonstrates the importance of including AGS on the differential diagnosis for individuals who screen positive for X-ALD, particularly infants with abnormal neurological features, as this age of onset would be highly unusual for X-ALD. While AGS is not included on the Recommended Universal Screening Panel, affected individuals can be identified early through state NBS programs so long as providers are aware of a broader differential that includes AGS. This report is timely, as state NBS algorithms for X-ALD are actively being established, implemented, and refined.

We are presenting the case of a 6-year-old male patient with progeroid phenotype and severe developmental delay referred to Genetic clinic. Given the complex phenotype an extensive metabolic and genetic evaluation was performed including a whole exome sequencing analysis that showed genetic variants in TTR, RELN, MYH6, PHIP, and SYNE2 genes. Patients’ mother and brother were analyzed for the genetic variants in MYH6, PHIP and RELN. Both had same variants on PHIP and RELN as our patient, with no apparent phenotypical consequences. Physical examination was remarkable for dysmorphism including plagiocephaly, low set and abnormally shaped ears, up slanted palpebral fissures, hypoplastic alae nasi, and a head circumference two standard deviations below the 3(rd) percentile (microcephaly). Other characteristics include wrinkled skin, a broad forehead, sparse eyelashes in lower eyelid, short palpebral fissures, upturned nares, thick lips, right occipital plagiocephaly, overfolded helix and prominent anti-helix, protuberant chest, scaphoid abdomen, digitalized thumbs, and kyphosis due to low muscle tone. The patient presented abnormal EEG with evidence of epileptic discharges. A temporal bone CT showed plagiocephaly with flattening of the right occipital bone. Brain MRI showed callosal agenesis with bilateral colpocephaly with temporal horn dilatation, parahippocampal atrophy, lissencephaly and midbrain hypoplasia. The combination of de novo gene variants mentioned above has never been reported nor correlated as the result of haploinsufficiency mechanisms. Thus, we propose haploinsufficiency and loss of heterozygosity as etiological reasons for this patient phenotype. Further proteomic studies are needed to allocate the extense of genetic influence within the clinical manifestations.

Background Pathogenic variants in the IGHMBP2 gene cause recessive spinal motor neuropathies of variable phenotype, including a predominantly distal motor impairment of Charcot-Marie-Tooth type 2S and the more severe condition of spinal muscular atrophy with respiratory distress type 1 in which infantile respiratory failure predominates. Methods We describe the first reported case of spinal muscular atrophy with respiratory distress type 1 caused by a novel deep intronic variant in IGHMBP2 (NM_002180c.712-610A>G). Results The variant was detected by whole genome sequencing. Reverse transcription–polymerase chain reaction and complimentary DNA sequencing were used to characterize the impact of the novel variant. Conclusions This report illustrates the utility in clinical practice of genome sequencing and RNA analysis, compared with exome sequencing alone.