A novel FGF8 mutation in a female patient with isolated congenital anosmia.
Ontology highlight
ABSTRACT:
SUBMITTER: Stamou MI
PROVIDER: S-EPMC8832634 | biostudies-literature | 2019 Jun
REPOSITORIES: biostudies-literature
Publications
A novel FGF8 mutation in a female patient with isolated congenital anosmia.
Stamou M I MI Plummer L L Koika V V Galli-Tsinopoulou A A Georgopoulos N A NA
Hormones (Athens, Greece) 20190513 2
Similar Datasets
Project description:Isolated congenital anosmia (ICA) is a rare condition that is associated with life-long inability to smell. Here we report a genetic characterization of a large Iranian family segregating ICA. Whole exome sequencing in five affected family members and five healthy members revealed a stop gain mutation in CNGA2 (OMIM 300338) (chrX:150,911,102; CNGA2. c.577C > T; p.Arg193*). The mutation segregates in an X-linked pattern, as all the affected family members are hemizygotes, whereas healthy family members are either heterozygote or homozygote for the reference allele. cnga2 knockout mice are congenitally anosmic and have abnormal olfactory system physiology, additionally Karstensen et al. recently reported two anosmic brothers sharing a CNGA2 truncating variant. Our study in concert with these findings provides strong support for role of CNGA2 gene with pathogenicity of ICA in humans. Together, these results indicate that mutations in key olfactory signaling pathway genes are responsible for human disease.
| S-EPMC5454015 | biostudies-literature
Project description:A 14-year-old adolescent was referred to a regional paediatric outpatient clinic with anosmia by her family doctor in Western Australia. The patient has no recollection of her previous ability to smell, suggesting the possibility of congenital anosmia. She was assessed in the paediatric outpatient clinic. A "noncontrast high-resolution MRI-brain scan with Anosmia-Protocol" was requested as the first-line investigation of choice by the treating paediatrician. The MRI was reported as "absence of olfactory tracts with preserved olfactory bulb volume." We report an extremely rare case of "isolated agenesis of the olfactory tract with intact olfactory bulbs" and discuss the clinical approach in bedside assessment of isolated congenital anosmia (ICA). Congenital anosmia can be a presentation of olfactory bulb aplasia; however, little is known about isolated olfactory tract agenesis and its treatment options. The patient was counselled on the diagnosis and safety advice provided.
| S-EPMC9283015 | biostudies-literature
Project description:ObjectiveTo investigate the GCM2 gene in three siblings with congenital hypoparathyroidism and perform functional analysis.Materials and methodsWe sequenced the GCM2 gene by PCR and analyzed the functional consequence of the mutation by transient transfection studies. Haplotype analysis was performed.ResultsWe identified a nucleotide change, c.408C>A, in exon 3 that is predicted to truncate the Gcm2 protein (p.Tyr136Ter). All three affected siblings were homozygous and both parents were heterozygous for the mutation. Transfection studies revealed the mutant mRNA but not expression of the Gcm2 protein. Haplotype analysis revealed that the two mutant GCM2 alleles shared genotypes on chromosome 6p24.2.ConclusionsWe describe the first GCM2 mutation in exon 3 in patients with severe congenital hypoparathyroidism. Informative genetic markers could not exclude identity by descent for the mutant alleles. Gcm2 protein was not detected after transfection, suggesting that complete lack of Gcm2 action accounts for severe hypoparathyroidism.
| S-EPMC3694175 | biostudies-literature
Project description:Congenital muscle dystrophies (CMD) are genetically and clinically heterogeneous hereditary myopathies mainly with autosomal recessive type of inheritance. The most common form worldwide is considered to be merosin-deficient muscle dystrophy type 1A, called MDC1A (due to laminin-α2 defects as a result of LAMA2 gene mutation), accounting for 30-40% of total cases of CMD. The exact molecular and clinical diagnoses, respectively, are a prerequisite for the most effective treatment; sometimes orphan drugs exist for some rare diseases. One of such drugs is Tarix, which was FDA approved and announced in 2016 for treatment of MDC1A. Here we present a patient diagnosed postmortem as having early-onset LAMA2-related muscular dystrophy as a result of mutations in LAMA2, identified by Sanger sequencing in his parents: a novel nonsense mutation c.4452T>A in exon 31, identified in the mother, and a known pathogenic nonsense mutation c.2901C>A in exon 21, detected in the father. The truncating nature of both nonsense mutations made the clinical presentation severe and the outcome fatal. Genetic analysis in such cases of muscle dystrophy is of utmost impact, because it makes the correct diagnosis with at least some specific options for treatment, makes the prognosis depending on the severity of mutation discovered, determines reproductive risk, and offers prophylaxis in the family by means of prenatal or preimplantation diagnostics.
| S-EPMC6083551 | biostudies-literature
Project description:Background: Isolated hypogonadotropic hypogonadism (IHH) is a rare, clinically heterogeneous condition, caused by the deficient secretion or action of gonadotropin releasing hormone (GnRH). It can manifest with absent or incomplete sexual maturation, or as infertility at adult-age; in a half of cases, IHH is associated with hypo/anosmia (Kallmann syndrome). Although a growing number of genes are being related to this disease, genetic mutations are currently found only in 40% of IHH patients. Case description: Severe congenital hyposmia was diagnosed in a 25-year-old Caucasian man referred to the Ear-Nose-Throat department of our clinic. The patient had no cryptorchidism or micropenis and experienced a physiological puberty; past medical history and physical examination were unremarkable. Olfactory structures appeared hypoplasic, while hypothalamus, pituitary gland, and stalk were normal on MRI (neuroradiological imaging); testosterone levels, as well as pulsatile gonadotropin secretion and other pituitary hormones were unaffected at the time of first referral. At the age of 48, the patient returned to our clinic for sexual complaints, and the finding of low testosterone levels (6.8 and 5.8 nmol/L on two consecutive assessments) with inappropriately normal gonadotropin levels led to the diagnosis of hypogonadotropic hypogonadism. GnRH test was consistent with hypothalamic origin of the defect. Next generation sequencing was then performed revealing a rare heterozygous allelic variant in SPRY4 gene (c.158G>A, p.R53Q). The biological and clinical effects of this gene variant had never been reported before. A diagnosis of Kallmann syndrome was finally established, and the patient was started on testosterone replacement therapy. Conclusion: This case describes the clinical phenotype associated with a rare SPRY4 gene allelic variant, consisting in congenital severe smell defect and adult-onset IHH; in patients with apparently isolated congenital anosmia genetic analysis can be valuable to guide follow up, since IHH can manifest later in adulthood. Characterization of other modifying genes and acquired environmental factors is needed for a better understanding of the physiopathology and clinical manifestations of this disease.
| S-EPMC6861180 | biostudies-literature
Project description:Genetic causes of congenital anosmia
| PRJNA988248 | ENA
Project description:Genetic causes of congenital anosmia
| PRJNA988249 | ENA
Project description:We performed whole exome or genome sequencing in eight multiply affected families with ostensibly isolated congenital anosmia. Hypothesis-free analyses based on the assumption of fully penetrant recessive/dominant/X-linked models obtained no strong single candidate variant in any of these families. In total, these eight families showed 548 rare segregating variants that were predicted to be damaging, in 510 genes. Three Kallmann syndrome genes (FGFR1, SEMA3A, and CHD7) were identified. We performed permutation-based analysis to test for overall enrichment of these 510 genes carrying these 548 variants with genes mutated in Kallmann syndrome and with a control set of genes mutated in hypogonadotrophic hypogonadism without anosmia. The variants were found to be enriched for Kallmann syndrome genes (3 observed vs. 0.398 expected, p = 0.007), but not for the second set of genes. Among these three variants, two have been already reported in genes related to syndromic anosmia (FGFR1 (p.(R250W)), CHD7 (p.(L2806V))) and one was novel (SEMA3A (p.(T717I))). To replicate these findings, we performed targeted sequencing of 16 genes involved in Kallmann syndrome and hypogonadotrophic hypogonadism in 29 additional families, mostly singletons. This yielded an additional 6 variants in 5 Kallmann syndrome genes (PROKR2, SEMA3A, CHD7, PROK2, ANOS1), two of them already reported to cause Kallmann syndrome. In all, our study suggests involvement of 6 syndromic Kallmann genes in isolated anosmia. Further, we report a yet unreported appearance of di-genic inheritance in a family with congenital isolated anosmia. These results are consistent with a complex molecular basis of congenital anosmia.
| S-EPMC5865213 | biostudies-literature
Project description:Congenital anosmias can be complete (the lack of a sense of smell) or specific (the inability to detect specific smells). Here we obtained genomic DNA from families with multiple individuals with anosmia, suggesting they are congenital. These include those inherited in a manner consistent with dominant and recessive alleles. We have sequenced the exomes of both affected and unaffected family members on the Illumina platform.
| EGAS00001001429 | EGA
Project description:Congenital anosmias can be complete (the lack of a sense of smell) or specific (the inability to detect specific smells). To date, only a single recessive gene underlying complete anosmia has been identified. Here we sequenced the exomes of 10 individuals from a single family, including three with complete anosmia, across three generations to identify the genetic basis of congenital anosmia in this family.
This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
| EGAS00001001124 | EGA