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Alu elements are short, interspersed elements located throughout the genome, playing a role in human diversity, and occasionally causing genetic diseases. Here, we report a novel Alu insertion causing Mowat-Wilson syndrome, a rare neurodevelopmental disorder, in an 8-year-old boy displaying the typical clinical features for Mowat-Wilson syndrome. The variant was not initially detected in genome sequencing data, but through deep phenotyping, which pointed to only one plausible candidate gene, manual inspection of genome sequencing alignment data enabled us to identify a de novo heterozygous Alu insertion in exon 8 of the ZEB2 gene. Nanopore long-read sequencing confirmed the Alu insertion, leading to the formation of a premature stop codon and likely haploinsufficiency of ZEB2. This underscores the importance of deep phenotyping and mobile element insertion analysis in uncovering genetic causes of monogenic disorders as these elements might be overlooked in standard next-generation sequencing protocols., (© 2024 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Objective: To quantify soft tissue facial asymmetry (FA) in children with nonsyndromic and Muenke syndrome-associated unicoronal synostosis (NS-UCS and MS-UCS), hypothesizing that MS-UCS presents with significantly larger FA than NS-UCS., Design: Retrospective cohort study., Patients and Methods: Twenty-one children (mean age: 0.6 years; range: 0.1-1.4 years) were included in the study (NS-UCS = 14; MS-UCS = 7). From presurgical computed tomography scans, facial surfaces were constructed for analysis. A landmark guided atlas was deformed to match each patient's surface, obtaining spatially detailed left-right point correspondence. Facial asymmetry was calculated in each surface point across the face, as the length (mm) of an asymmetry vector, with its Cartesian components providing 3 directions. Mean FA was calculated for the full face, and the forehead, eye, nose, cheek, mouth, and chin regions., Results: For the full face, a significant difference of 2.4 mm ( P = .001) was calculated between the 2 groups, predominately in the transverse direction (1.5 mm; P < .001). The forehead and chin regions presented with the largest significant difference, 3.5 mm ( P = .002) and 3.2 mm ( P < .001), respectively; followed by the eye (2.4 mm; P = .004), cheek (2.2 mm; P = .004), nose (1.7 mm; P = .001), and mouth (1.4 mm; P = .009) regions. The transverse direction presented with the largest significant difference in the forehead, chin, mouth, and nose regions, the sagittal direction in the cheek region, and the vertical direction in the eye region., Conclusions: Muenke syndrome-associated unicoronal synostosis presented with significantly larger FA in all regions compared to NS-UCS. The largest significant differences were found in the forehead and chin regions, predominantly in the transverse direction.

Primrose syndrome (OMIM 259050) is a rare disorder characterised by macrocephaly with developmental delay, a recognisable facial phenotype, altered glucose metabolism, and other features such as sensorineural hearing loss, short stature, and calcification of the ear cartilage. It is caused by heterozygous variants in ZBTB20, a member of the POK family of transcription repressors. Recently, this gene was shown to have a role in skeletal development through its action on chondrocyte differentiation by repression of SOX9. We describe five unrelated patients with Primrose syndrome and distinct skeletal features including multiple Wormian bones, platybasia, bitemporal bossing, bathrocephaly, slender bones, epiphyseal and spondylar dysplasia. The radiological abnormalities of the skull and the epiphyseal dysplasia were the most consistent findings. This novel constellation of skeletal features expands the phenotypic spectrum of the disorder., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Primrose syndrome (PS; MIM# 259050) is characterized by intellectual disability (ID), macrocephaly, unusual facial features (frontal bossing, deeply set eyes, down-slanting palpebral fissures), calcified external ears, sparse body hair and distal muscle wasting. The syndrome is caused by de novo heterozygous missense variants in ZBTB20. Most of the 29 published patients are adults as characteristics appear more recognizable with age. We present 13 hitherto unpublished individuals and summarize the clinical and molecular findings in all 42 patients. Several signs and symptoms of PS develop during childhood, but the cardinal features, such as calcification of the external ears, cystic bone lesions, muscle wasting, and contractures typically develop between 10 and 16 years of age. Biochemically, anemia and increased alpha-fetoprotein levels are often present. Two adult males with PS developed a testicular tumor. Although PS should be regarded as a progressive entity, there are no indications that cognition becomes more impaired with age. No obvious genotype-phenotype correlation is present. A subgroup of patients with ZBTB20 variants may be associated with mild, nonspecific ID. Metabolic investigations suggest a disturbed mitochondrial fatty acid oxidation. We suggest a regular surveillance in all adult males with PS until it is clear whether or not there is a truly elevated risk of testicular cancer., (© 2020 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)

Autosomal recessive omodysplasia ( GPC6 -related) is a rare short-limb skeletal dysplasia caused by biallelic mutations in the GPC6 gene. Affected individuals manifest with rhizomelic short stature, decreased mobility of elbow and knee joints as well as craniofacial anomalies. Both upper and lower limbs are severely affected. These manifestations contrast with normal height and limb shortening restricted to the arms in autosomal dominant omodysplasia ( FZD2 -related). Here, we report 2 affected brothers of Pakistani descent from Denmark with GPC6 -related omodysplasia, aiming to highlight the clinical and radiological findings. A homozygous deletion of exon 6 in the GPC6 gene was detected. The pathognomonic radiological findings were distally tapered humeri and femora as well as severe proximal radioulnar diastasis. On close observations, we identified a recurrent and not previously described type of abnormal patterning in all long bones., (Copyright © 2020 by S. Karger AG, Basel.)

Purpose: Four patients with Saul-Wilson syndrome were reported between 1982 and 1994, but no additional individuals were described until 2018, when the molecular etiology of the disease was elucidated. Hence, the clinical phenotype of the disease remains poorly defined. We address this shortcoming by providing a detailed characterization of its phenotype., Methods: Retrospective chart reviews were performed and primary radiographs assessed for all 14 individuals. Four individuals underwent detailed ophthalmologic examination by the same physician. Two individuals underwent gynecologic evaluation. Z-scores for height, weight, head circumference and body mass index were calculated at different ages., Results: All patients exhibited short stature, with sharp decline from the mean within the first months of life, and a final height Z-score between -4 and -8.5 standard deviations. The facial and radiographic features evolved over time. Intermittent neutropenia was frequently observed. Novel findings included elevation of liver transaminases, skeletal fragility, rod-cone dystrophy, and cystic macular changes., Conclusions: Saul-Wilson syndrome presents a remarkably uniform phenotype, and the comprehensive description of our cohort allows for improved understanding of the long-term morbidity of the condition, establishment of follow-up recommendations for affected individuals, and documentation of the natural history into adulthood for comparison with treated patients, when therapeutics become available.

Pycnodysostosis (PYCD) is a rare recessive inherited skeletal disease, characterized by short stature, brittle bones, and recurrent fractures, caused by variants in the Cathepsin K encoding gene that leads to impaired osteoclast-mediated bone resorption. Hypophosphatasia (HPP) is a dominant or recessive inherited condition representing a heterogeneous phenotype with dental symptoms, recurrent fractures, and musculoskeletal problems. The disease results from mutation(s) in the tissue non-specific alkaline phosphate encoding gene with reduced activity of alkaline phosphatase and secondarily defective mineralization of bone and teeth. Here, we present the first report of a patient with the coexistence of PYCD and HPP. This patient presented typical clinical findings of PYCD, including short stature, maxillary hypoplasia, and sleep apnoea. However, the burden of disease was caused by over 30 fractures, whereupon most showed delayed healing and non-union. Biochemical analysis revealed suppressed bone resorption and low bone formation capacity. We suggest that the coexistence of impaired bone resorption and mineralization may explain the severe bone phenotype with poor fracture healing.

Objective: To assess improvement of soft-tissue facial symmetry in children surgically treated for unicoronal synostosis (UCS) in infancy, to correlate pre- and postsurgical facial asymmetry and to evaluate whether the improvement was visually recognizable., Design: Case-controlled follow-up., Patients/settings: Eleven Danish children diagnosed with UCS were included, 3 of whom had tested positive for Muenke mutation. Preoperative computed tomography scans and postoperative 3dMD surfaces were available for measurements. A control group of healthy children matched for age and sex was employed., Main Outcome Measures: Pre- and postsurgical facial asymmetry was analyzed using a computerized method capable of objective and spatially detailed quantification in 3-dimension (transverse, vertical, and sagittal directions). Asymmetry was evaluated in the facial region and 6 subregions (forehead, mouth, eyes, nose, cheek, and chin)., Results: The largest significant improvement was seen in the sagittal direction of the facial (1.9 mm), forehead (2.0 mm), and cheek (3.4 mm) regions. Small but significant improvements were also seen in the mouth, chin, and eye regions. No significant improvement was seen in the nose region. Significant correlations were found between the pre- and postsurgically calculated facial asymmetry and between calculated asymmetry and clinical validation scores., Conclusions: All patients presented with improved facial symmetry after surgery and the improvements were visually recognizable. However, only 1 (9.1%) of the 11 patients reached a level of facial asymmetry as low as that seen in the control group. The best outcome was, in general, seen in cases with mild facial asymmetry presurgically.

The conserved oligomeric Golgi (COG) complex is involved in intracellular vesicular transport, and is composed of eight subunits distributed in two lobes, lobe A (COG1-4) and lobe B (COG5-8). We describe fourteen individuals with Saul-Wilson syndrome, a rare form of primordial dwarfism with characteristic facial and radiographic features. All affected subjects harbored heterozygous de novo variants in COG4, giving rise to the same recurrent amino acid substitution (p.Gly516Arg). Affected individuals' fibroblasts, whose COG4 mRNA and protein were not decreased, exhibited delayed anterograde vesicular trafficking from the ER to the Golgi and accelerated retrograde vesicular recycling from the Golgi to the ER. This altered steady-state equilibrium led to a decrease in Golgi volume, as well as morphologic abnormalities with collapse of the Golgi stacks. Despite these abnormalities of the Golgi apparatus, protein glycosylation in sera and fibroblasts from affected subjects was not notably altered, but decorin, a proteoglycan secreted into the extracellular matrix, showed altered Golgi-dependent glycosylation. In summary, we define a specific heterozygous COG4 substitution as the molecular basis of Saul-Wilson syndrome, a rare skeletal dysplasia distinct from biallelic COG4-CDG., (Published by Elsevier Inc.)

In this case study, we investigate a child presenting with patent ductus arteriosus, short philtrum, duck-bill lips, strabismus, a flat nasal bridge, a broad forehead, low-set ears, hypertelorism, up-slanting palpebral fissures, almond-shaped eyes, and hypodontia, all leading to the clinical diagnosis of Char syndrome. Genetic analysis showed heterozygosity for the novel variant c.851T>C, p. Leu284Ser in the TFAP2B gene. Family analysis suggested that at least 20 members, extending six generations back, were affected. All 10 members available for genetic testing were heterozygous for the novel pathogenic variant. Qualitative analysis of the facial dysmorphology in the proband and three of the affected family members using three-dimensional surface scanning showed that the major deviations were observed in the forehead/eyebrow, nose, upper lip, and chin regions with, for example, a flattened nose and reduced height of the upper lip and the face. Furthermore, it is suggested that Char syndrome is associated with disturbances of tooth formation and eruption.

Oculoectodermal syndrome (OES) and encephalocraniocutaneous lipomatosis (ECCL) are rare disorders that share many common features, such as epibulbar dermoids, aplasia cutis congenita, pigmentary changes following Blaschko lines, bony tumor-like lesions, and others. About 20 cases with OES and more than 50 patients with ECCL have been reported. Both diseases were proposed to represent mosaic disorders, but only very recently whole-genome sequencing has led to the identification of somatic KRAS mutations, p.Leu19Phe and p.Gly13Asp, in affected tissue from two individuals with OES. Here we report the results of molecular genetic studies in three patients with OES and one with ECCL. In all four cases, Sanger sequencing of the KRAS gene in DNA from lesional tissue detected mutations affecting codon 146 (p.Ala146Val, p.Ala146Thr) at variable levels of mosaicism. Our findings thus corroborate the evidence of OES being a mosaic RASopathy and confirm the common etiology of OES and ECCL. KRAS codon 146 mutations, as well as the previously reported OES-associated alterations, are known oncogenic KRAS mutations with distinct functional consequences. Considering the phenotype and genotype spectrum of mosaic RASopathies, these findings suggest that the wide phenotypic variability does not only depend on the tissue distribution but also on the specific genotype., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)