Merve Soğukpınar

Introduction: Sandestig-Stefanova syndrome is a new and extremely rare autosomal recessive genetic disorder characterized by microcephaly, ocular anomalies, distinctive facial features, cleft lip/palate, digital anomalies, congenital heart disease, central nervous system anomalies, hypotonia, central respiratory failure, and poor prognosis. Biallelic loss-of-function variants in the NUP188 gene are the cause of Sandestig-Stefanova syndrome. To date, only 11 patients have been reported in the literature. Case Presentation: In this study, we present a novel homozygous pathogenic frameshift variant in the NUP188 gene in a Turkish female patient. The patient was born small for gestational age and exhibited microcephaly, cataracts, dysmorphic facial features, ventricular septal defect and secundum atrial septal defect, right kidney axis rotation anomaly, ventriculomegaly, and digital anomalies. The parents were healthy and consanguineous (first cousins). Family history was notable for a previously deceased sibling with a similar clinical presentation. Our patient displayed clinical symptoms similar to those reported in previous studies; however, she also exhibited additional findings, including optic disc hypoplasia, right kidney axis rotation anomaly, and faint palmar creases. Conclusion: These additional findings expand the clinical spectrum of this extremely rare disease. Identifying a novel pathogenic variant improves our understanding of the molecular causes of the disorder and broadens its genotypic spectrum.

Introduction: Phelan-McDermid syndrome (PMS) is a neurodevelopmental disorder most often caused by terminal 22q13.3 deletions involving SHANK3. Although primarily associated with developmental delay, hypotonia, and autism spectrum disorder-like features, rare reports have described atypical teratoid/rhabdoid tumor (AT/RT) in PMS, suggesting a potential oncogenic link. Case Presentation: We report the clinical, molecular, and treatment features of a child with PMS and AT/RT and review previously published cases. The proband presented with global developmental delay, absent speech, hypotonia, joint laxity, and characteristic dysmorphic features. Chromosomal microarray revealed a ∼2.26 Mb terminal deletion at 22q13.32q13.33, encompassing 31 OMIM-listed genes including SHANK3. At 6 months of age, he was diagnosed with AT/RT and treated with multimodal chemotherapy and craniospinal radiotherapy, achieving remission. Literature review identified additional PMS patients with AT/RT, supporting a role for 22q instability in tumorigenesis. Conclusion: This case highlights a rare but clinically significant association between PMS and AT/RT. Awareness of this potential link and careful radiotherapy planning are warranted to optimize outcomes in affected individuals.

WDR83OS ‐related neurodevelopmental disorder is a rare autosomal recessive condition characterized by developmental delay, dysmorphic features and variable hepatic involvement, particularly hypercholanaemia. Here, we report a female patient presenting with global developmental delay, syndromic facial features and scaphocephaly due to sagittal craniosynostosis, representing a previously unreported phenotypic feature. The patient was born to consanguineous parents and exhibited delayed motor and language milestones. Physical examination revealed characteristic dysmorphic features, whereas routine laboratory findings, including liver function tests, were within normal limits. Serum bile acid levels were not assessed. Cranial imaging confirmed sagittal craniosynostosis. Whole exome sequencing identified a novel homozygous nonsense variant in WDR83OS , classified as likely pathogenic according to ACMG criteria. No additional candidate variants, including those associated with craniosynostosis, were detected. This case possibly expands the phenotypic spectrum of WDR83OS ‐related disorder by identifying scaphocephaly as a novel feature. Our findings highlight the importance of comprehensive genomic evaluation in syndromic neurodevelopmental disorders and suggest that WDR83OS should be considered in the differential diagnosis of patients with craniosynostosis and developmental delay, even in the absence of overt hepatic involvement.

Introduction: Jaberi-Elahi syndrome is a rare autosomal recessive neurodevelopmental disorder caused by biallelic loss-of-function variants in GTPBP2, a gene involved in ribosome-associated quality control. The condition shows marked phenotypic heterogeneity, including microcephaly, hypotonia or spasticity, developmental delay, intellectual disability, movement disorders, epilepsy, and variable neuroimaging findings. Case Presentation: We report a 4-month-old female infant born to consanguineous parents, presenting with severe microcephaly, developmental delay, hypotonia, and craniofacial features. Additional findings included left-sided pes equinovarus, secundum atrial septal defect, and periventricular white matter abnormalities on brain magnetic resonance imaging. No overt ectodermal abnormalities were observed. Ophthalmological examination revealed no structural anomalies; however, detailed retinal evaluation and electroretinography could not be performed. During follow-up, the patient developed early-onset seizures requiring antiepileptic treatment. Clinic exome sequencing identified a novel homozygous frameshift variant in GTPBP2 (c.1165_1166del; p.(Leu389GlufsTer26)), classified as likely pathogenic. This homozygous variant was absent in population databases, and segregation analysis confirmed parental heterozygosity. This represents the first reported case with Jaberi-Elahi syndrome from Türkiye. Conclusion: Jaberi-Elahi syndrome should be considered in infants with severe congenital microcephaly, developmental delay, seizures, and craniofacial features, particularly in the context of consanguinity and abnormal brain magnetic resonance imaging. This report expands the molecular and clinical spectrum of Jaberi-Elahi syndrome.

KBG syndrome is a rare autosomal dominant disorder caused by ANKRD11 variants, characterized by distinctive craniofacial features, short stature, skeletal anomalies, and neurodevelopmental impairment. Regional studies, particularly from underrepresented populations, are essential to broaden the clinical and molecular spectrum of the syndrome. We retrospectively analyzed the clinical, molecular, and anthropometric data of 23 Turkish individuals with molecularly confirmed KBG syndrome. Molecular analyses included whole exome sequencing, clinical exome sequencing, and targeted gene panels. Variants were classified according to ACMG guidelines, and phenotypic features were systematically assessed using standardized criteria. Eighteen distinct ANKRD11 pathogenic or likely pathogenic variants were identified, including eight novel variants, predominantly located in exon 9. Short stature (height SDS < –2) was documented in 30.4% of patients. Intellectual disability was observed in 82.6%, and behavioral anomalies in 52.2% of the cohort. Craniofacial dysmorphism, including long philtrum, triangular facial shape, and macrodontia, was prominent. No genotype–phenotype correlation could be established. This study expands the mutational landscape of ANKRD11 and underscores the clinical variability of KBG syndrome in a Turkish cohort. Our findings emphasize the importance of integrating molecular and detailed clinical evaluations for early diagnosis, especially in diverse populations with limited prior representation.

Achondroplasia (ACH; MIM #100,800), caused by a heterozygous gain of function pathogenic variant in the fibroblast growth factor receptor 3 gene (FGFR3; MIM*134,934), is the most prevalent and most readily identifiable cause of disproportionate short stature that is compatible with life. In addition, individuals with achondroplasia face significant medical, functional, and psychosocial challenges throughout their lives. This study assessed associated morbidities in patients with achondroplasia at a single center in Turkey. In this study, the clinical findings and associated morbidities of a group of patients with achondroplasia (n = 68) with clinical multidisciplinary follow-up at a single center between the years 2005–2023 are evaluated retrospectively. A total of 68 patients, 30 male (44.1%) and 38 female (55.9%), were evaluated. In the majority (84.2%) of patients, shortness of extremities was detected in the prenatal period at an average of 28.7 gestational weeks (± 3.6 SDS) with the aid of ultrasonography. More than half (n = 34/63, 54%) of the patients had a father of advanced paternal age (≥ 35 years). Among the complications, respiratory system manifestations, including obstructive sleep apnea (70%), ear-nose-throat manifestations including adenoid hypertrophy (56.6%) and otitis media (54.7%), neurological manifestations due to foramen magnum stenosis (53.2%), and skeletal manifestations including scoliosis (28.8%), are represented among the most common. The mortality rate was 7.3% (n = 5/68).Conclusion: This study not only represents the first retrospective analysis of the associated morbidities of patients with achondroplasia from a single center in Turkey but also will provide a reference point for future studies.

Dyggve–Melchior–Clausen dysplasia (DMC) and Smith–McCort dysplasia (SMC types 1 and 2) are rare spondylo‐epi‐metaphyseal dysplasias with identical radiological and clinical findings. DMC and SMC type 1 are allelic disorders caused by homozygous or compound heterozygous variants in DYM, while biallelic causative variants in RAB33B lead to SMC type 2. The terminology “skeletal golgipathies” has been recently used to describe these conditions, highlighting the pivotal role of these two genes in the organization and intracellular trafficking of the Golgi apparatus. In this study, we investigated 17 affected individuals (8 males, 9 females) from 10 unrelated consanguineous families, 10 diagnosed with DMC and seven with SMC type 2. The mean age at diagnosis was 9.61 ± 9.72 years, ranging from 20 months to 34 years, and the average height at diagnosis was 92.85 ± 15.50 cm. All patients exhibited variable degrees of short trunk with a barrel chest, protruding abdomen, hyperlordosis, and decreased joint mobility. A total of nine different biallelic variants were identified, with six being located in the DYM gene and the remaining three detected in RAB33B. Notably, five variants were classified as novel, four in the DYM gene and one in the RAB33B gene. This study aims to comprehensively assess clinical, radiological, and molecular findings along with the long‐term follow‐up findings in 17 patients with DMC and SMC type 2. Our results suggest that clinical symptoms of the disorder typically appear from infancy to early childhood. The central notches of the vertebral bodies were identified as early as 20 months and tended to become rectangular, particularly around 15 years of age. Pseudoepiphysis was observed in five patients; we believe this finding should be taken into consideration when evaluating hand radiographs in clinical assessments. Furthermore, our research contributes to an enhanced understanding of clinical and molecular aspects in these rare “skeletal golgipathies,” expanding the mutational spectrum and offering insights into long‐term disease outcomes.

Introduction: Primrose syndrome (PS; MIM #259050) is a rare autosomal dominant genetic condition characterized by macrocephaly with or without tall stature, hypotonia, moderate to severe intellectual disability (ID) with delay in expressive speech development, behavioral abnormalities, and a recognizable facial phenotype including deep set eyes, ptosis, narrow and frequently downslanting palpebral fissures, and depressed nasal bridge. PS is caused by a heterozygous pathogenic variant in ZBTB20 (MIM #606025) on chromosome 3q13. Among other characteristic findings are ocular abnormalities, hearing loss, calcification of the external ear cartilage, nonspecific brain magnetic resonance imaging findings, and cryptorchidism. Adults may exhibit joint contractures, distal muscle wasting, sparse body hair, cataract, and disturbed glucose metabolism as well. The majority of affected individuals have typically been adults until recently since the phenotype becomes more recognizable in time. Case Presentation: In this study, we report on a 14-month-old girl who presented with neurodevelopmental findings, facial features, and hearing loss. The glucose metabolism was normal, and muscle atrophy, joint contractures, and external ear cartilage calcification were yet hitherto not evident. A novel de novo missense variant in ZBTB20 was identified with the aid of exome sequencing. Conclusion: PS is a rare clinical entity with various recognizable features, yet the phenotype may be indistinguishable from other neurodevelopmental disorders. Exome sequencing is a useful diagnostic tool especially in patients with no specific diagnosis despite detailed examinations and imaging studies.