POGZ-related disorders (also known as White-Sutton syndrome) encompass a wide range of neurocognitive abnormalities and other accompanying anomalies. Disease severity varies widely among POGZ patients and studies investigating genotype-phenotype association are scarce. Therefore, our aim was to collect data on previously unreported POGZ patients and perform a large-scale phenotype-genotype comparison from published data. Overall, 117 POGZ patients’ genotype and phenotype data were included in the analysis, including 12 novel patients. A severity scoring system was developed for the comparison. Mild and severe phenotypes were compared with the types and location of the variants and the predicted presence or absence of nonsense-mediated RNA decay (NMD). Missense variants were more often associated with mild phenotypes (p = 0.0421) and truncating variants predicted to escape NMD presented with more severe phenotypes (p < 0.0001). Within this group, variants in the prolin-rich region of the POGZ protein were associated with the most severe phenotypes (p = 0.0004). Our study suggests that gain-of-function or dominant negative effect through escaping NMD and the location of the variants in the prolin-rich domain of the protein may play an important role in the severity of manifestations of POGZ–associated neurodevelopmental disorders.

The recessive PIEZO2-associated disease, distal arthrogryposis with impaired proprioception and touch (DAIPT), is characterized by hypotonia, perinatal respiratory distress, significantly delayed motor milestones, and progressive symptoms of distal arthrogryposis and scoliosis. Here, we describe the youngest patient with DAIPT to date, who, at the age of 3.5 years, did not show a single clinical sign of distal arthrogryposis or contractures, but had a history of bilateral clubfoot operations. On the contrary, he presented with some features, not described thus far, such as syringohydromyelia, a small cyst of the spinal cord, moderate microcephaly with premature closure of anterior fontanelle, and spontaneous unilateral patella dislocation at the age of 32 months. Using whole exome sequencing, we identified 2 new different loss-of-function mutations in the PIEZO2 gene in our patient. We also review the phenotypes of all 16 previously published patients with DAIPT, summarize the distinctive clinical features of this rare genetic disorder, and recommend that DAIPT be included in the differential diagnosis of floppy infant. PIEZO2 is a unique ion channel that converts mechanical impulses into cellular signals and is involved in various mechanotransduction pathways. In addition to DAIPT, mutations in PIEZO2 have been described to cause 3 more distinct phenotypes of distal arthrogryposis, which are dominant and associated with gain-of-function mutations. On the contrary, recessive DAIPT is associated with loss-of-function PIEZO2 mutations.

The collection of theNarrenturmin Vienna houses and maintains more than 50,000 objects including approximately 1200 teratological specimens; making it one of the biggest collections of specimens from human origin in Europe. The existence of this magnificent collection―representing an important resource for dysmorphology research, mostly awaiting contemporary diagnoses―is not widely known in the scientific community. Here, we show that theNarrenturmharbors a wealth of specimens with (exceptionally) rare congenital anomalies. These museums can be seen as physical repositories of human malformation, covering hundreds of years of dedicated collecting and preserving, thereby creating unique settings that can be used to expand our knowledge of developmental conditions that have to be preserved for future generations of scientists.

Lateral facial clefts are rare and often part of more complex syndromic neurocristopathies. According to Tessier’s classification, they correspond to facial cleft numbers 6, 7 and 8. Using micro-computer tomography (micro-CT), we analyzed their underlying bone defects (resolution 50 and 55 µm/voxel) in the context of the known syndrome-specific genetic background. Lateral facial clefts were diagnosed in three severely affected museum specimens representing mandibulofacial dysostosis type Treacher Collins syndrome (TCS), acrofacial dysostosis syndrome of Rodriguez (AFD-Rod) and tetra-amelia syndrome (TETAMS). The TCS specimen mainly showed an absence of the zygomatic bones and most of the lateral maxilla. The AFD-Rod specimen showed an extensive defect of the lateral maxilla, zygomatic bones, and mandible. The TETAMS specimen showed almost isolated agnathia. Possible relationships are discussed between the diverse facial bone defects due to apoptosis of neural crest-derived cells, known to be associated with ribosomopathies and spliceosomopathies, such as TCS and AFD-Rod, and the more targeted bone defects due to genetic variants known to cause TETAMS.

Hepatobiliary excretion of conjugated bilirubin is mediated by an ATP dependent canalicular transporter, the multidrug resistence associated protein 2 (MRP2/ABCC2). MRP2 is responsible for biliary excrection of glucuronide and glutathione conjugates of endogenous and exogenous compounds. Before this excretion, bilirubin is conjugated by uridine‐diphosphoglucuronosyl transferase 1A1 (UGT1A1) with glucuronic acid. Dubin‐Johnson syndrome (DJS) is an inherited autosomal recessive disorder characterised by the absence of functional protein MRP2 at the canalicular membrane of hepatocytes. Known mutations in this gene cause impaired maturation and trafficking of the mutated protein from the endoplasmic reticulum to the Golgi complex. As a result, conjugated hyperbilirubinemia is found. Defects of UGT1A1 gene cause deficient glucuronidation manifested in unconjugated hyperbilirubinemia – Gilbert syndrome. Here we present a study of a large gypsy family with mixed congenital hyperbilirubinemia Dubin‐Johnson syndrome and Gilbert syndrome. The novel mutation 1012delGT in MRP2 gene, which causes a frameshift was found. Twenty nine subjects were investigated, two of them were found to be homozygous for both named hyperbilirubinemia. This is the first large molecular study of mixed hyperbilirubinemia with a description of both homozygous forms of mutations in UGT1A1 and MRP2 genes.

We report an autosomal recessive neurodevelopmental disorder exclusively affecting females carrying biallelic loss-of-function variants in CIZ1 , a gene encoding a nuclear matrix protein essential for the maintenance of X-chromosome inactivation. Eight unrelated affected females were identified, whereas male siblings with biallelic variants were asymptomatic. We showed that loss of CIZ1 compromises the maintenance of X-chromosome inactivation, leading to an abnormal overexpression of a subset of X-linked genes.