Complex Inheritance of ABCA4 Disease: Four Mutations in a Family with Multiple Macular Phenotypes
PMID: 26527198
Gene: ABCA4
HGNC ID: 34
Complex Inheritance of ABCA4 Disease: Four Mutations in a Family with Multiple Macular Phenotypes
PMID: 26527198
Gene: ABCA4
HGNC ID: 34
man in hismid-40s
Case#: Male, mid-40s
DiseaseAssertion: STGD1
FamilyInfo: Retinal disease reported in sibling and material grandfather. Mother exhibited decreased visual acuity, BEM in right eye, and tapetal reflex in both eyes.
CasePresentingHPOs: HP:0000622, HP:0000613, HP:0000662, HP:0011504, HP:0007663, HP:0011463
CaseHPOFreeText: n/a
CaseNotHPOs: HP:0007843, HP:0011507
CaseNotHPOFreeText: Autofluorescence(qAF): 381.5. The Case's qAF was noted to be in the range observed in healthy eyes, and also lower than many other STGD1 patients with the same age. There were no flecks, intraretinal pigment migration, retinal vessel attenuation, or optic nerve pallor (Figure 1).
Genotyping Method: Sanger Sequencing
PreviouslyPublished: n/a
Variant: NM_000350.3(ABCA4):c.1411G>A (p.Glu471Lys), NM_001034853.2(RPGR):c.3070G>T (p.Glu1024Ter)
ClinVar: 99052, 1275798
SupplementalData: n/a
Quantitative Autofluorescence as a Clinical Tool for Expedited Differential Diagnosis of Retinal Degeneration
PMID: 25375877
Gene: ABCA4, RPGR
HGNC ID: 34, 10295
5-year-old girl
Case#:5-year-old girl
DiseaseAssertion: Asymptomatic
FamilyInfo: Mother was diagnosed with STGD1 and She was homozygous for a (severe) splice site mutation, IVS 35+2 T>C, Maternal uncle was diagnosed with STGD1. Father passed down the G1961E variant.
CasePresentingHPOs: HP:0030630, HP:0011504
CaseHPOFreeText: The ELM in the central macula appeared thickened with indistinct borders, particularly along its inner border (Fig. 2C), horizontal diameter for the region of thickened ELM was 1113 μm, FAF revealed Bull’s Eye Maculopathy (BEM) (Fig. 2B),
CaseNotHPOs:
CaseNotHPOFreeText: No retinal, vasculature, pigmentary or optic nerve head abnormalities were detected on clinical examination, no focal abnormality observed in the outer nuclear layer (ONL) or RPE (Fig. 2C), There was no FAF evidence of flecks or GA
Genotyping Method:
PreviouslyPublished: No
Variant:NM_000350.3:c.5882G>,
ClinVar:7888
CAID:CA119132
SupplementalData:
Disruption in Bruch membrane in patients with Stargardt disease
PMID: 22060670
Gene: ABCA4
HGNC ID: 34
Case 3
Case#: Case 3, Sex: Male, Age:21
DiseaseAssertion: STGD
FamilyInfo: n/a
CasePresentingHPOs:
CaseHPOFreeText: Text mentions BCVA of 20/200 in both eyes. Pigmentary changes in macula associated with flecks, small inferior juxta-papillar area of subretinal fibrosis in right eye, left eye legion localized in posterior pole macula temporally. Instable fixation in right eye. Low retinal mean sensitivity in both eyes.
CaseNotHPOs:n/a
CaseNotHPOFreeText: Healthy ocular adnexa and specular transparent and 'in situ' lens. Visual acuity stable. Stable fixation in left eye.
Genotyping Method: genetic analysis
PreviouslyPublished: n/a
Variant: Variant is a heterozygous mutation given as NM_000350.3(ABCA4):c.3212C>T (p.Ser1071Leu) / NM_000350.3(ABCA4):c.667A>C (p.Lys223Gln) / NM_000350.3(ABCA4):c.3607G>A (p.Gly1203Arg)
ClinVar: Variation ID: 99208 / Variation ID: 845426/ Variation ID: 417989
SupplementalData: n/a
Case 3: RP3.03
Case#: RP3.03, 23yo, 21yo on set, Moroccan
DiseaseAssertion: Retinitis Pigmentosa (RP19)
FamilyInfo: Born into a consanguineous family, parents are unaffected, has five unaffected siblings
CasePresentingHPOs: HP:0000505, HP:0007675, HP:0001133, HP:0007994, HP:0007843, HP:0000510, HP:0000580, HP:0007703
CaseHPOFreeText: Abnormal epiretinal membrane formation, Altered ERG traces, rod and cone photoreceptor dysfunctions, hyper fuorescence ring surrounding macula and peripheral retina, absence of cystic spaces
CaseNotHPOs: HP:0000551
CaseNotHPOFreeText: Central vision loss
Genotyping Method: Genomic DNA was extracted using QIAamp DND Blood Mini Kit, DNA underwent WES by BGI Tech Solutions, DNA was captured by MGIEasy Exome Capture V4 Probe Set, then Alligned using the Burrows-Wheeler Aligner and HaplotypeCaller of GAWK
PreviouslyPublished: CRB1, PDE6B
Variant: c.5908C>T, c.6148G>C
ClinVar: 7892, 7884
SupplementalData: Clinical data (table 1, figure 5), Genetic analysis (table 2), Patient Pedigree (figure 1.)
ABCA4
Case#: 1 male, 6 years old, from Taiwanese and Korean decent.
DiseaseAssertion: ABCA4-related retinopathy Stargardt disease
FamilyInfo: Single affected individual. Paternal uncle presented with Stargart disease previously, and Taiwanese and Korean descent underwent genetic testing to identify two pathogenic variants in the ABCA4 gene. One of the variants found was the same ABCA4 variant from the originally affected individual. No additional family information is provided in text.
CasePresentingHPOs: HP:0000529 - progressive visual loss, HP:0025010 - Foveal atrophy, HP:0000603 - Central scotoma, HP:0007663 - Decreased visual acuity, HP:0030602 - Abnormal fundus autofluorescence imaging, HP:0007984 - ERG: Reduced dark-adapted b-wave amplitude, HP:0000512 - Abnormal electroretinogram, HP:0020032 - Hyperreflective retinal dots on OCT
CaseHPOFreeText: peripapillary sparing was observed on fundus autofluorescence imaging.
CaseNotHPOs: HP:0012045 - Retinal flecks
CaseNotHPOFreeText: N/A
Genotyping Method: Genetic testing was used and after sequencing two variants were found on the ABCA4 gene.
PreviouslyPublished: N/A
Variant: NM_000350.3(ABCA4):c.3523-2A>G
Variant: NM_000350.3(ABCA4):c.2249T>C (p.Leu750Pro)
ClinVar: Variation ID: 866764
ClinVar: Variation ID: 417984
CAID: N/A
SupplementalData: N/A
Case 2
Case#:2, 29-year-old woman
DiseaseAssertion:NR
FamilyInfo:NR
CasePresentingHPOs:
CaseHPOFreeText:decreased ability to focus, increasing difficulty to adapt in the dark, normal visual acuity in both eyes (logMar BCVA OD/OS: 0.02), PERG responses were diminished in both eyes.
CaseNotHPOs:
CaseNotHPOFreeText:
Genotyping Method: ”Analysis of the ABCA4 gene”
PreviouslyPublished:No
Variant:NM_000350.3:c.1805G>A, NM_000350.3:c.6079C>T
ClinVar: 99085, 7882
CAID:CA226933, CA119129
SupplementalData:
In this study, we report a 4-month-old boy with T−B+NK− SCID due to an unreported nonsense mutation in exon 2 of the IL2RG gene. The patient was derived from a twin pregnancy, and his twin brother was asymptomatic with no immune defects. In order to confirm the pathogenic effect of the detected novel variant on the protein structure, a modeling process was performed.
Case: Patient, Male, 4 months old <br /> DiseaseAssertion: SCID <br /> FamilyInfo: third child of non-consanguineous parents; has twin brother that is asymptomatic with no immune defects; no family history of primary immunodeficiencies <br /> CasePresentingHPOs: HP:0002014, HP:0020099, HP:0030148 <br /> CaseHPOFreeText: diarrhea, norovirus infection, heart murmur <br /> CaseNotHPOs: increased CRP <br /> CasePreviousTesting: N/A <br /> Gene: IL2RG <br /> Variant: NM_000206(IL2RG): <br /> ClinVar: <br /> CAID: <br /> gnomAD: <br /> SupplementalData:
A 55-year-old male
Case#: 55-year-old man
DiseaseAssertion: single coronary artery (SCA) and presented with dilated cardiomyopathy (DCM)
FamilyInfo: Unremarkable
ParentalTesting: NR
CasePresentingHPOs: HP:0002094, HP:0031352, HP:0001638, HP:0001644, HP:0010741
CaseHPOFreeText: chest tightness and dyspnoea after activity lasting for 2 months. CTCA showed congenital absence of the right coronary artery. TTE revealed enlargement of the left heart and cardiomyopathy. CMR revealed DCM. oedema of both lower limbs. Laboratory data in Table 1.
CaseNotHPOs: NR
CaseNotHPOFreeText: Stenosis
CasePreviousTesting: See NGS results in Supplementary Table 1
Genotyping Method: Genetic screening (NGS results in Supplementary Table 1) with confirmation by Sanger
FunctionalAnalysis: NR
Variant: c.1858C>T (p.Arg620Cys)
ClinVar: 67694
CAID: CA015449
gnomAD: v4.1.0 GrpMax FAF: 0.00002033 (European non-Finnish)
AdditionalInfo: The patient also has APOA5:c.990_993delAACA (p. Asp332Valfs*5) (P/LP in ClinVar with 2 stars)
DICER1 syndrome encompasses a variety of benign and malignant manifestations including multinodular goitre
Gene: DICER1 PMCID: PMC8451242 PMID: 34552563 Pathogenic Inheritance Pattern: Autosomal Dominant MultipleDiseaseEntities Disease Entity: DICER1 syndrome, multinodular goitre, cystic nephroma, anaplastic renal sarcoma, Wilms tumour, differentiated thyroid carcinoma, gynandroblastoma, ciliary body medulloepithelioma, embryonal rhabdomyosarcoma, pineoblastoma, pituitary blastoma, kidney cyst, pulmonary cyst, Sertoli-Leydig Cell Tumor. Mutation: Germline MultipleGeneVariants Variant & Clinvar IDs: c.3452_3453del (485534), c.316del (no ClinVar ID), c.171_172insAC (no ClinVar ID), c.3434del (no ClinVar ID), c.988C>T (933007), c.5388dup (no ClinVar ID) Zygosity: None provided. Case: At time of operation, the goitre patients living in Denmark were ages 21, 12, 21, 8, 14, and 16. Four underwent total thyroidectomies, and two underwent partial thyroidectomies. The patient originally aged 21 previously had a kidney cyst at age 14 and a pulmonary cyst at an unknown age. The patient aged 14 at time of partial thyroidectomy later manifested a Sertoli-Leydig Cell Tumor at age 15. All six patients were female. CasePresentingHPO: None provided. CasePreviousTesting: thyroidectomy gnomAD: ENSG00000100697.10, https://gnomad.broadinstitute.org/gene/ENSG00000100697 Mutation Type: Frameshift, Nonsense
DICER1 gene is located on chromosome 14q32.13 and plays a crucial role in the control of protein translation; its product, dicer protein, is a ribonuclease (RNase) III endoribonuclease which is essential for the production of microRNAs (miRNA) which are formed by the cleavage of pre-miRNA or double-stranded RNA1–4. RNase III contains two domains, IIIa and IIIb which cleave 3p miRNA and 5p miRNA from the 3′ and 5′ pre-miRNA, respectively. These cleavages require magnesium ions at the interface between the IIIa and IIIb domains and the miRNA; this magnesium dependent catalytic processing occurs at specific residues, E1320, E1564, E1813 and D17092–4. miRNA has a pivotal role in regulating the expression of over 30% of protein-coding genes by its interaction with mRNA5. Given the impact of DICER1 in post-translational events, it is not entirely surprising that functional DICER1 is essential for vertebrate development as evidenced by developmental arrest and death of the embryo when both alleles are lost6,7. Conceptually, DICER1 can be regarded as either a tumor suppressor gene due to loss-of-function mutations or an oncogene due to gain-of-function mutations; it is thought to function as a haploinsufficient tumor suppressor gene with the loss of one allele leading to tumor progression but loss of both alleles having an inhibitory effect for tumor development implying that one intact allele is needed for cell survival8.A study led by one of the authors (DAH) identified germline loss-of-function DICER1 mutations affecting the RNase IIIb domain in affected families with pleuropulmonary blastoma (PPB)9, a rare dysembryonic lung malignancy of childhood which was not the only manifestation of this familial tumor predisposition syndrome; germline and somatic DICER1 mutations were subsequently identified in several other familial associated tumors in several extrapulmonary sites (Table 1). Individuals with germline DICER1 mutations also had non-neoplastic conditions including macrocephaly, renal structural anomalies, retinal abnormalities, dental perturbations, and the GLOW syndrome (global developmental delay, lung cysts, overgrowth and Wilms tumor). These associations encircle the DICER1 tumor predisposition syndrome (Online Mendelian Inheritance in Man numbers 606241, 601200 and 138800), with the estimation that 90% of those affected by this syndrome inherited a germline mutation from one of their parents, with a pattern of autosomal dominant inheritance10.
DICER1 syndrome is an autosomal-dominant, familial pleiotropic tumor-predisposition disorder1 caused by pathogenic germline variants in DICER1, an essential component of the microRNA processing pathway.
GeneName: DICER1 PMID: 30715996 HGNCID: N/A Inherritence pattern: autosomal dominant Disease Entity: multiple gene variants mutation: germline Zygosity: N/A Variant: Not found Family Info: N/A
The DICER1 syndrome
Gene: DICER1 PMID: 30672147 HGNCID: n/a Inheritance Pattern: autosomal dominant Disease Entity: Pleuropulmonary Blastoma, Cystic Nephroma, Sertoli-Leydig tumors, Multinodular goiter, thyroid cancer, rhabdomysarcoma, pineoblastoma Mutation: Germline Zygosity: n/a MultipleGeneVariants Variant: p.Gly1824Val, p.Ser1160Tyr, p.Ala1578Thr, p.Leu1469Pro, p.Ser1160Tyr, p.Ile528Thr, p.Pro1836Leu, p.Glu904*, p.Tyr1835Ser, p.Ile528Thr, p.Arg1342His, p.Phe1650Cys, p.Trp1481Arg, p.Arg201His, p.Asp1390His, p.Trp1397Arg, p.Ala1578Thr <br /> Family Info: n/a gnomAD: n/a
DICER1 syndrome (OMIM 606241, 601200)
Gene Name: OMIN PMID: 34599283 Autosomal Dominant Gynandroblastoma cERMS Pediatric Paratesticular Sarcomas nephrolithiasis or nephrocalcinonsis Cystic Nephroma Anaplastic Sarcoma of Kidney Wilms tumor Cystic Hepatic Neoplasm Hamartomatous polyps
Germline mutation heterozygosity Multiple Gene Variants There is usually a family history or a carrier for the mutation it rarely occurs out of nowhere.