Expansion of phenotype of DDX3X syndrome: six new cases Pathogenic variants in DDX3X have recently been identified to be a relatively common cause of intellectual disability in females. In this study, we describe six female probands, from five unrelated families, with five novel heterozygous variants in DDX3X, and the identification of potential germline mosaicism. Consistent features between this cohort and previously described cases include developmental delay or intellectual disability, growth disturbance and movement disorder. Common facial dysmorphism within the cohort include short palpebral fissures, micrognathia, bulbous nasal tip, protruding ears, high arched palate, thin upper vermillion and smooth philtrum. Novel clinical features identified from this cohort include facial dysmorphisms, perinatal complications, valgus feet deformity, lipoatrophy, dystonic episodes, and cutaneous mastocytosis. This case series attempts to expand the phenotype of the DDX3X syndrome; however, it remains heterogeneous. Description of further cases is required to more accurately identify the significance of novel phenotypes within this cohort.

Further phenotypic characterization of Kaufman oculocerebrofacial syndrome: report of five new cases and literature review Kaufman oculocerebrofacial syndrome is a rare autosomal recessive disorder caused by biallelic variants in UBE3B. Kaufman oculocerebrofacial syndrome is characterized by a recognizable pattern of malformations including moderate to severe intellectual disability, growth deficiency, microcephaly and a distinctive facial gestalt. Common craniofacial features include short upslanting palpebral fissures, blepharophimosis or ptosis, ear anomalies, hearing loss, palate anomalies and stridor/laryngomalacia. The aim of this study was to describe the phenotypic features and the genotype of five new individuals from three unrelated families, and to review systematically the published information of 26 cases. The main features are summarized contributing to further characterize the natural history of the disease. Novel phenotypic features and two novel pathogenic variants in UBE3B are reported: A splice site variant (c.2569-1G > C) and a nonsense variant (c.518C > A, p.Ser173Ter). Kaufman oculocerebrofacial syndrome is likely an underdiagnosed disorder which can be clinically recognized based on its distinctive facial gestalt and relatively homogenous natural history.

Traboulsi syndrome due to ASPH mutation: an under-recognised cause of ectopia lentis Traboulsi syndrome is an extremely rare ophthalmological disorder characterised by facial dysmorphism, lens dislocation, anterior segment abnormalities and spontaneous filtering blebs. It is caused by pathogenic variants in the ASPH gene. To date, only 13 individuals with Traboulsi syndrome from three families have been reported in the literature. We report the first UK family with Traboulsi syndrome associated with two novel ASPH variants. This condition, which has some phenotypic overlap with both Marfan syndrome and homocystinuria, is most likely under ascertained, and we further delineate the clinical features to aid its recognition.

GATAD2B-related intellectual disability due to parental mosaicism and review of literature GATA zinc finger domain-containing 2B (GATAD2B) encodes p66beta, a subunit of transcription repressor complex methyl-CpG-binding protein-1 histone deacetylase complex/nucleosome remodelling and deacetylase, and mediates gene silencing. Pathogenic variants in GATAD2B are known to cause mental retardation, autosomal dominant 18, characterized by intellectual disability, limited speech development, generalized hypotonia and dysmorphism. Till date, 17 cases of GATAD2B-related intellectual disability, resulting either from loss-of-function variants in GATAD2B or microdeletions spanning GATAD2B, have been reported. Singleton exome sequencing was performed for index patient. The pathogenic variant identified was validated and segregation analysis was performed by Sanger sequencing. In this study, we report on an additional subject with GATAD2B-related intellectual disability identified through whole exome sequencing. The clinically unaffected father harboured the pathogenic variant in a mosaic state. We review the existing phenotypic and genotypic information for the individuals with this condition. GATAD2B-related intellectual disability is a rare condition with subtle yet recognizable clinical features. In this article, we highlight a consistent clinical profile of subjects with GATAD2B-related intellectual disability.

16p13.11-p12.3 Microdeletion identified in a patient with sagittal craniosynostosis and developmental delay No abstract available

Phenotypic delineation of a 12q21 deletion syndrome No abstract available

Mosaic paternal uniparental isodisomy of 15q11-q13 region causing Angelman phenotype No abstract available

SATB2-associated syndrome: first report of a gonadal and somatic mosaicism for an intragenic copy number variation Gonadal mosaicism has been reported in a variety of dominant or X-linked conditions and should be considered in all cases of apparent de-novo variation. Recently, some cases of supposed parental germline mosaicism have been shown to result from low-level somatic mosaicism. In most of the cases, mosaicism has been reported for pathogenic single nucleotide variants with only a few cases of copy number variation mosaicism described so far. Herein, we present the first case of parental somatic and gonadal copy number variation mosaicism in the SATB2 gene. We report three brothers presenting with the SATB2-associated syndrome. They all carry the same 121-kb heterozygous intragenic deletion of SATB2. Parental somatic mosaicism was detected by array-comparative genomic hybridization on a maternal blood sample and confirmed by Fluorescence in situ hybridization analysis on blood and buccal cells. This clinical report highlights the importance of investigating for parental somatic mosaicism to estimate the proper recurrence risk for subsequent pregnancy.

Changing facial features in a child with GAPO syndrome caused by novel mutation in the ANTXR1 gene and uniparental disomy of chromosome 2 No abstract available

TFAP2A mutation in a child and mother with predominantly ocular anomalies: non-classical presentation of branchio-oculo-facial syndrome No abstract available