Case Reports in Genetics最新文献

We encountered a case with congenital iris coloboma, omphalocele, and developmental delay with a 2.5 Mb deletion on chromosome 4q25 encompassing PITX2, leading to Axenfeld-Rieger syndrome (ARS), NEUROG2, and ANK2. ARS is characterized by the aplasia of the anterior eye, odontogenesis, and abdominal wall aplasia. In our case, iris coloboma and omphalocele were thought to be caused by PITX2 haploinsufficiency. However, these symptoms are nonspecific, and clinical symptoms alone can make it difficult to make a correct diagnosis. In addition, the genes responsible for developmental delay, among others, are not well understood. Developmental delay, in this case, might be caused due to NEUROG2 haploinsufficiency. In spite of the partial deletion of ANK2, the causative gene of long QT syndrome type 4, the electrocardiogram was normal. Genetic testing can lead to a correct diagnosis, and it may be effective in detecting complications.

Autosomal recessive intellectual developmental disorder type 5 (MRT5, OMIM # 611091) is caused by biallelic pathogenic variants, leading to loss of function of the NSUN2 gene which encodes a methyltransferase involved in several biological processes, ranging from stress response to neurodevelopment (Hussain 2021). The current literature shows that MRT5 typically manifests with intellectual disability, facial dysmorphism, juvenile cataracts, chronic nephritis, hearing impairment, seizures, cerebellar atrophy, and microcephaly (Pingree et al. 2021). We describe a case of a patient with MRT5 who developed epilepsy in his teens, a rare clinical presentation that has not yet been discussed at length in the literature. Our patient is a 15-year-old male with a history of autism, developmental delay, and focal epilepsy who underwent genetic testing and was found to have a homozygous frameshift mutation in NSUN2 predicted to cause loss of function. This case emphasizes that epilepsy can be a phenotypic manifestation in patients with MRT5.

We report a patient diagnosed with a COL4A1 mutation in the early postnatal period. Patients with early postnatal jaundice, intracranial lesions that are negative for TORCH syndrome, and recurrent hemolytic anemia should be suspected of having a COL4A1/COL4A2 gene mutation.

The DIAPH1 gene fulfills critical immune and neurodevelopmental roles. It encodes the mammalian Diaphanous-related formin (mDia1) protein, which acts downstream of Rho GTPases to promote F-actin polymerization and stabilize microtubules. During mitosis, this protein is expressed in human neuronal precursor cells and considerably affects spindle formation and cell division. In humans, dominant gain-of-function DIAPH1 variants cause sensorineural deafness and macrothrombocytopenia (DFNA1), while homozygous DIAPH1 loss leads to seizures, cortical blindness, and microcephaly syndrome (SCBMS). To date, only 16 patients with SCBMS have been reported, none of whom were from Iran. Furthermore, aspergillosis is yet to be reported in patients with homozygous DIAPH1 loss, and the link between SCBMS and immunodeficiency remains elusive. In this study, we shed further light on this matter by reporting the clinical, genetic, and phenotypic characteristics of an Iranian boy with a long history of recurrent infections, diagnosed with SCBMS and immunodeficiency (NM_005219.5 c.3145C > T; p.R1049X variant) following aspergillosis and SARS-CoV-2 coinfection.

BRCA-1-associated protein-1 (BAP1) tumour predisposition syndrome (BAP1-TPDS) is a dominant hereditary cancer syndrome. The full spectrum of associated malignancies is yet to be fully characterised. We detail the phenotypic features of the first reported family with a whole BAP1 gene deletion. This report also adds to the emerging evidence that the rhabdoid subtype of meningioma is a part of the clinical spectrum of this tumour predisposition syndrome.

Pyridoxine dependent-developmental and epileptic encephalopathy (PD-DEE) or pyridoxine-dependent epilepsy (PDE) is a rare autosomal recessive disorder caused by biallelic pathogenic variants in ALDH7A1. It classically presents as intractable infantile-onset seizures unresponsive to multiple antiepileptic drugs (AEDs) but with a profound response to large doses of pyridoxine (B6). We report a case of PDE with an atypical clinical presentation. The patient presented at 3 days of life with multifocal seizures, fever, increased work of breathing, decreased left ventricular systolic function, and lactic acidosis, raising suspicion for a mitochondrial disorder or infectious process. Within 1.5 weeks of presentation, seizure activity resolved with antiepileptic therapy. Whole exome sequencing (WES) revealed homozygous pathogenic variants in ALDH7A1 (c.1279G > C, p.E427Q) and confirmed the diagnosis of PDE. Follow-up biochemical testing demonstrated elevated urine pipecolic acid. In the second week of life, the patient was initiated on triple therapy, including pyridoxine supplementation, low lysine diet, and arginine supplementation, which he tolerated well. Urine pipecolic acid levels responded accordingly after initiation of therapy. Our case illustrates the diagnostic challenges in PDE, the utility of rapid WES in such cases, and the response in urine pipecolic acid to therapy.

Fibrodysplasia ossificans progressiva (FOP) is a rare skeletal disorder characterized by congenital malformation of the great toes and progressive heterotopic ossification. Malformation of the great toes appears at birth, while heterotopic ossification generally occurs during childhood and rarely occurs during infancy. Classical FOP results from the heterozygous p.Arg206His variant of the ACVR1 gene, which encodes Activin A receptor type 1. Recently, some atypical FOP patients with other ACVR1 gene variants and clinical features that are not observed in classical FOP patients have been reported. Herein, we describe a girl with severe FOP and multiple anomalies, including syndactyly of the hands and feet, nail agenesis, mandibular hypoplasia, heterotopic ossification occurring from infancy, and congenital cardiac malformation. In our patient, we identified de novo occurrence of the heterozygous p.Arg258Gly variant of ACVR1, which has previously been reported in only two severe FOP patients. Heterotopic ossification occurred earlier and more frequently compared with classical FOP patients. We present the time-series changes in heterotopic ossification in our patient and compare her clinical features with those of the previously reported patients with p.Arg258Gly. Our report deepens understanding of the clinical features in severe FOP with p.Arg258Gly and of FOP as a systemic disorder.

We describe a male patient with a novel TTI2 variant, which has not been previously associated with a human phenotype. His features include intellectual disability, primary microcephaly, delayed psychomotor development, speech delay, short stature, dysmorphic facial features, esotropia, kyphoscoliosis, and behavior abnormalities (Figure). Next generation sequencing revealed autosomal recessive TTI2 variant with uncertain significance, denoted as c.21_22insAAGCGCTCTG (p.Glu8Lysfs × 12). TTI2 encodes a regulator of DNA damage response and helps maintain steady levels of the PIKK family of protein kinases. No disease-causing variants in other genes potentially linked to his clinical presentation were identified. We report a novel loss-of-function homozygous variant in TTI2 that leads to syndromic intellectual disability and primary microcephaly.

Fibro-adipose vascular anomaly (FAVA) is a recently described complex and painful benign lesion found in young adults and the pediatric population composed of intramuscular vascular, fibrous, and adipose tissues. A previous report has identified the presence of somatic mosaic mutations in the gene for the catalytic subunit of phosphatidylinositol 3-kinase (PIK3CA) in cases of FAVA. Herein, we present a case of FAVA found in a 23-year-old male patient who presented with chronic wrist pain associated with a mass, and we identified an associated somatic activating mutation (H1047R) in PIK3CA. We briefly review the relevant literature surrounding the identification and histology of FAVA, the known mutational spectrum, downstream signaling pathways, and relevant treatment modalities. Our case highlights the association between FAVA and somatic mosaic activating PIK3CA mutations.

Introduction: Vici syndrome (also known as immunodeficiency with cleft lip/palate, cataract, and hypopigmentation and absent corpus callosum) is considered as a progressive neurodevelopmental multisystem disorder. Till date, only 80 cases, including our patient, with this syndrome have been reported .This syndrome is characterized by agenesis of the corpus callosum, hypopigmentation of the eyes and hair, cataract, cardiomyopathy, combined immunodeficiency, hearing loss, seizures, and additional multisystem involvements which have been reported as case reports in the past. Clinical Manifestation. A 5-year-old girl, who is a product of consanguineous marriage, was referred to our center with developmental delay, optic atrophy, blindness, spasticity, seizure, movement disability, and spasticity. Her magnetic resonance imaging (MRI) test showed agenesis of the corpus callosum and her metabolic test reported normal.

Materials and methods: In our laboratory, blood sample was obtained from the patient. DNA was extracted from lymphocytes, and whole exome sequencing (WES) using next generation Illumina sequencing was performed.

Result: A novel (private), homozygous, nonsynonymous mutation c.A3206G (p.Y1069C Het) in EPG5 gene was detected; in continuum, testing for this specific variant in her parents was carried out. DNA sequencing of the PCR-amplified product of the EPG5 exon 17 showed that her parents were heterozygote for this variant. These mutations have not been reported before and therefore classified as variation of unknown significance (VUS). Mutation in this gene is shown to cause autosomal recessive Vici syndrome.

Conclusion: Since clinical features of Vici syndrome has overlap, its diagnosis is differential and developmental delay occurs in 98% of reported cases. Vici syndrome can be considered as one of the main causes of developmental delay, and this syndrome can be introduced as a novel group of inherited neurometabolic conditions and congenital disorders.