Project description:BackgroundHereditary spherocytosis (HS) is a type of hemolytic anemia caused by abnormal red cell membrane skeletal proteins with few unique clinical manifestations in the neonate and infant. An ANK1 gene mutation is the most common cause of HS.Case presentationThe patient was a 11-month-old boy who suffered from anemia and needed a regular transfusion therapy at an interval of 2-3 months. Hematological investigations showed moderate anemia (Hb80 g/L). Red cells displayed microcytosis (MCV76.4 fl, MCH25.6 pg, MCHC335 g/L). The reticulocytes were elevated (4.8%) and the spherocytes were increased (10%). Direct antiglobulin test was negative. Biochemical test indicated a slight elevation of bilirubin, mainly indirect reacting (TBIL32.5 μmol/L, IBIL24 μmol/L). The neonatal HS ratio is 4.38, obviously up the threshold. Meanwhile, a de novo ANK1 mutation (exon 25:c.2693dupC:p.A899Sfs*11) was identified by next-generation sequencing (NGS). Thus, hereditary spherocytosis was finally diagnosed.ConclusionsGene detection should be considered in some hemolytic anemia which is difficult to diagnose by routine means. We identified a novel de novo ANK1 heterozygous frameshift mutation in a Yi nationality patient while neither of his parents carried this mutation.
Project description:BACKGROUND: Fabry disease is an X-linked inherited metabolic condition where the deficit of the ?-galactosidase A enzyme, encoded by the GLA gene, leads to glycosphingolipid storage, mainly globotriaosylceramide. To date, more than 600 mutations have been identified in human GLA gene that are responsible for FD, including missense and nonsense mutations, small and large deletions. Such mutations are usually inherited, and cases of de novo onset occur rarely. CASE PRESENTATION: In this article we report an interesting case of a 44-year-old male patient suffering from a severe form of Fabry disease, with negative family history. The patient showed signs such as cornea verticillata, angiokeratomas, cardiac and neurological manifestations, an end-stage renal disease and he had low ?-galactosidase A activity. We detected, in this subject, the mutation c.493 G > C in the third exon of the GLA gene which causes the amino acid substitution D165H in the protein. This mutation affects the amino acid - belonging to the group of buried residues - involved, probably, in the preservation of the protein folding. Moreover, studies of multiple sequence alignment indicate that this amino acid is highly conserved, thus strengthening the hypothesis that it is a key amino acid to the enzyme functionality.The study of the relatives of the patient showed that, surprisingly, none of the members of his family of origin had this genetic alteration, suggesting a de novo mutation. Only his 11-year-old daughter - showing acroparaesthesias and heat intolerance with reduced enzymatic activity - had the same mutation. CONCLUSIONS: We suggest that a non-inherited mutation of the ?-galactosidase A gene is responsible for Fabry disease in the patient who had reduced enzyme activity and classical clinical manifestations of the disease. In a family, it is rare to find only one Fabry disease affected subject with a de novo mutation. These findings emphasize the importance of early diagnosis, genetic counselling, studying the genealogical tree of the patients and starting enzyme replacement therapy to prevent irreversible vital organ damage that occurs during the course of the disease.
Project description:RationaleWiedemann-Steiner syndrome (WDSTS, online mendelian inheritance in man 605130) is a rare autosomal dominant disorder characterized by hypertrichosis cubiti. Here, we report a Chinese boy who do not show the characteristic of hypertrichosis cubiti, and was misdiagnosed as blepharophimosis-ptosis-epicanthus inversus syndrome at first. We found a de novo frameshift mutation (p.Glu390Lysfs*10) in the KMT2A gene, which was not reported before. Our study increases the cohort of Chinese WDSTS patients, and expand the WDSTS phenotypic and variation spectrum.Patient concernsThe patient demonstrated typical craniofacial features of blepharophimosis-ptosis-epicanthus inversus syndrome, including small palpebral fissures, ptosis, telecanthus, and epicanthus inversus, besides he had congenital heart disease (ventricular septal defects), strabismus, hypotonia, amblyopia, delayed speech and language development, delayed psychomotor development, and amblyopia (HP:0000646) which was not reported before.DiagnosisFOXL2 gene was cloned and sequenced, however, there was no mutation detected in this patient. The result of Chromosomal microarray analysis was normal. The patient was diagnosed as WDSTS by whole exome sequencing.InterventionsThe patient received cardiac surgery, frontalis suspension and regular speech and occupational therapy. He also treated with growth hormone (GH).OutcomesThe patient's symptoms are improved after cardiac surgery and frontalis suspension, he can express himself well now and had a 10 cm gain in height.LessonsAs the relationship between genotype and phenotype becomes more and more clear, WES is incredibly powerful tool to diagnose the disease of WDSTS.
Project description:Autosomal dominant mental retardation-7 (MRD7) is a rare anomaly, characterized by severe intellectual disability, feeding difficulties, behavior abnormalities, and distinctive facial features, including microcephaly, deep-set eyes, large simple ears, and a pointed or bulbous nasal tip. Some studies show that the disorder has a close correlation with variants in DYRK1A. Herein we described a Chinese girl presenting typical clinical features diagnosed at 4 years old. Whole-exome sequencing of the familial genomic DNA identified a novel mutation c.930C > A (p.Tyr310*) in exon 7 of DYRK1A in the proband. The nonsense mutation was predicted to render the truncation of the protein. Our results suggested that the de novo heterozygous mutation in DYRK1A was responsible for the MRD7 in this Chinese family, which both extended the knowledge of mutation spectrum in MRD7 patients and highlighted the clinical application of exome sequencing.
Project description:Mental retardation-40 (MRD40) is a rare autosomal dominant neurodevelopmental disorder with a poor prognosis that is caused by a heterozygous mutation in chromosome alignment maintaining phosphoprotein 1 (CHAMP1). It was previously considered a non-syndromic disease due to the lack of specific external features. Only limited international reports describing CHAMP1 mutations are currently available. The present case study was the first to report on a Chinese patient with MRD40. The patient presented with severe global development delay with significant craniofacial dysmorphia. Using trio whole-exome sequencing, a novel de novo frameshift mutation in CHAMP1, NM_032436.2: c.530delCinsTTT, was identified, which expands the spectrum of the known pathogenic variants. The present case report helps to improve the syndromic profile of the rare MRD40 disorder and provides an example for the clinical diagnosis of MRD40.
Project description:Diagnosis of pediatric intellectual disability (ID) can be difficult because it is due to a vast number of established and novel causes. Here, we described a full-term female infant affected by Kleefstra syndrome-2 presenting with neurodevelopmental disorder, a history of hypotonia and minor face anomalies. A systematic literature review was also performed. The patient was a 6-year-old Caucasian female. In the family history there was no intellectual disability or genetic conditions. Auxological parameters at birth were adequate for gestational age. Clinical evaluation at 6 months revealed hypotonia and, successively, delay in the acquisition of the stages of psychomotor development. Auditory, visual, somatosensory, and motor-evoked potentials were normal. A brain MRI, performed at 9 months, showed minimal gliotic changes in bilateral occipital periventricular white matter. Neuropsychiatric control, performed at 5 years, established a definitive diagnosis of childhood autism and developmental delay. Molecular analysis of the exome revealed a novel KMT2C missense variant: c.9244C > T (p.Pro3082Ser) at a heterozygous state, giving her a diagnosis of Kleefstra syndrome 2. Parents did not show the variant. Literature review (four retrieved eligible studies, 10 patients) showed that all individuals had mild, moderate, or severe ID; language and motor delay; and autism. Short stature, microcephaly, childhood hypotonia and plagiocephaly were also present. Conclusion. Kleefstra syndrome 2 is a difficult diagnosis of a rare condition with a high clinical phenotypic heterogeneity. This study suggests that it must be taken in account in the work-up of an orphan diagnosis of intellectual disability and/or autism spectrum disorder.
Project description:Mutations in the guanine nucleotide-binding protein (G protein), α activating activity polypeptide O (GNAO1) gene have recently been described in 6 patients with early infantile epileptic encephalopathies. In the present study, we report the phenotype and the clinical course of a 4-year-old female with an epileptic encephalopathy (Ohtahara syndrome) and profound intellectual disability due to a de novo GNAO1 mutation (c.692A>G; p.Tyr231Cys). Ohtahara syndrome is a devastating early infantile epileptic encephalopathy that can be caused by mutations in different genes, now also including GNAO1. The mutation was found using a targeted next generation sequencing gene panel and demonstrates targeted sequencing as a powerful tool for identifying mutations in genes where only a few de novo mutations have been identified.
Project description:BackgroundZhu-Tokita-Takenouchi-Kim syndrome (ZTTK syndrome) is a severe multi-systemic developmental disorder, caused by variants in the SON gene. A patient diagnosed with ZTTK syndrome who carried a de novo SON mutation and exhibited recurrent myocardial injury was described in this case.Case presentationA 7-year-old girl was admitted to the Cardiology Department of Beijing Children's Hospital in November 2019 due to myocardial injury following respiratory infection. She displayed elevated myocardial enzymes and severe T-wave changes on electrocardiogram. Over the past three years, she had experienced myocardial injury on three occasions. Additionally, she exhibited intellectual disability, congenital amblyopia, and dysmorphic facial features. Genetic analysis revealed a de novo heterozygous mutation c.3852_3856delGGTAT in the SON gene, which was confirmed by Sanger sequencing of her parents. She received anti-infection treatment and was administered metoprolol orally. Her condition was stable at the time of discharge. Over a 42-month follow-up period at the outpatient clinic, she complained intermittent fatigue and palpitation.ConclusionsThe identified SON mutation, which plays a crucial role in heart development and mitochondrial function, may be associated with an increased susceptibility to myocardial injury or cardiomyopathy. This case report contributes novel insights into this rare condition and suggests the expansion of the ZTTK syndrome phenotype.
Project description:Abstract Introduction: Progressive osseous heteroplasia (POH) is a rare bone disorder characterized by heterotopic ossification in the skin and muscles, resulting in contractures of the joints and progressive loss of function. Whereas 60-70% of the POH patients have paternally inherited inactivating mutations in GNAS gene, the remaining 30-40% harbor no specific etiologies. FAM111B gene mutations, located on chromosome 11q12.1, cause POIKTMP (hereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis), a rare autosomal dominant disorder with high frequency of de novo missense mutations, which are believed to cause extensive fibrosis and adiposis of many tissues, though the exact mechanism is unknown. To our knowledge there are no reports of FAM111B associated with POH. Case: We describe a 15-year-old African American boy who presented with generalized calcific nodules, contractures, and muscle weakness leading to immobility, beginning at the age of 6 years. Cutaneous exam showed generalized hard nodules varying from small to plaque-like ulcerated erupted skin lesions. Biochemical evaluation revealed 25(OH) vitamin D insufficiency (20 ng/mL), and normal levels of parathyroid hormone, FGF-23, alkaline phosphatase, calcium, and phosphorus. Skeletal survey radiographs showed extensive heterotopic ossification involving soft tissues and muscles surrounding the bilateral humeri, ulnae, femurs, and bilateral tibias/fibulas. Computed tomography of the chest, abdomen, and pelvis showed extensive muscle ossifications involving right latissimus dorsi, left scalene, bilateral pectoralis and external oblique abdominal, right iliacus, bilateral gluteal, left adductor, and left hamstring. There was also an involvement of the subcutaneous tissues of the right upper back and left lower quadrant of the abdomen, left posterior sacral region, bilateral hips, and the fascia superficial to the erector spinae muscles with no abnormal ossifications in the bones. The clinical and radiographic findings were consistent with POH. Whole Exome Sequencing revealed a de novo heterozygous frameshift mutation in FAM111B (OMIM # 615584) of c.1462delT (p.Cys488Valfs*21) variant, causing replacement of C-terminal region with 21 alternative amino acids. Multiple previously reported disease-associated variants appear to localize within the same domain, supporting the functional importance of this region, though none have been previously associated with POH. Thus, we consider this variant to be pathogenic. Conclusion: This is the first case of POH caused by a mutation in FAM111B gene. Whether POH phenotype could be explained by mutations in FAM111B gene traditionally reserved for POIKTMP remains unclear. Further evaluations are necessary to fully elucidate this finding and potential mechanism by which the FAM111B gene mutation contributes to POH.
Project description:Carbonic anhydrase (CA) II deficiency results in an uncommon type of autosomal recessive sclerosing bone dysplasia with renal tubular acidosis and intracerebral calcification. We report a classic case of CA II-associated osteopetrosis with a previously reported homozygous frameshift mutation. Child was evaluated for short stature and failure to thrive. He was diagnosed as osteopetrosis in view of the presence of hepatosplenomegaly and increased bone density though hematological parameters were normal. Further evaluation showed presence of associated distal renal tubular acidosis raising a possibility of CA II deficiency. Mutation analysis revealed a previously reported homozygous frameshift mutation c.143-146delCTGT (p.Ser48Phefs*9) in CA2. Child has normal growth after initiation of alkali therapy.