PatientID: 1

KindredID: 1

Case: F, 16Y0M, Ukrainian

DiseaseAssertion: Assumed VHL

FamilyInfo: Her brother (patient 2) also had polycythemia and was heterozygeous for the mutation. Mutation inherited from father. The father was not polycythemic, but his BFU-Es were hypersensitive to Epo.

CasePresentingHPOs: HP:0001901, HP:0005954, HP:0000077, HP:0001028 (polycythemia, pulmonary capillary hemangiomatosis, abnormality of the kidney, hemangioma )

CaseHPOFreeText: Patient had a hematocrit of 68%, erythropoietin level of 45 mIU/mL, and had hypersensitivity of erythroid progenitors to Epo. She was diagnosed with polycythemia of unknown duration; at the age of 10 years, a pulmonary angioma was found and treated by a coil embolization. She continued to be polycythemic. At the age of 15 years, an abdominal computed tomography (CT) scan revealed a left renal mass, which on nephrectomy was determined to be a subcapsular hemangioma; there was no evidence of an angioma elsewhere. One year after surgery, she still remains polycythemic but has no evidence of a new or recurrent tumor.

CaseNotHPOs: N/A

CaseNotHPOFreeText: N/A

CasePreviousTesting: N/A

PreviouslyPublished: N/A

SupplementalData: N/A

Variant: p.D126Y(c.376G>T)

LegacyVariant: N/A

CaseProblemVariantFreeText: N/A

ClinVarID: 2230 https://www.ncbi.nlm.nih.gov/clinvar/variation/2230/

CAID: CA020319 http://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/allele?hgvsOrDescriptor=NM_000551.3%3Ac.376G%3ET

gnomAD: N/A

VariantEvidence: Patient was heterozygous for the mutation.

MutationType: missense_variant;transversion

CivicName: D126Y(c.376G>T)

MultipleGeneVariants: N/A

Eight children with a history of polycythemia and elevated serum erythropoietin level were evaluated. Three germline mutations were identified in 4 patients while, mutations were not detected for other 4 patients. Peripheral blood samples were taken and PCR products of either each VHL exon or the cDNA were purified and sequenced using a DNA sequencing kit (BigDye Terminator Cycle Sequencing Ready Reaction; Applied Biosystems, Foster City, CA). The sequencing reaction was performed in the Peltier Model P200 thermocycler. The products were then analyzed on the ABI Prism 377 DNA Sequencer (Applied Biosystems) according to the manufacturer's protocol. Clonality was determined by a transcriptional assay of exonic polymorphisms in 5 X-linked genes. An in vitro assay of erythroid progenitors' sensitivity to Epo was also performed. This missense mutation was found in a family of three patients. Patient 1, was a 16 year old Ukrainian girl who was heterozygous for the c. 376G>C mutation. She was diagnosed with polycythemia at age 10 and since then had presented with pulmonary capillary hemangiomatosis, abnormality of the kidney, hemangioma and her polycythemia had maintained. Her brother, patient 2, was 10 years old and also heterozygous for the mutation but only presented with polycythemia. He had an abnormally high erythropoietin level (271 mIU/mL). The children were found to have inherited the mutation from their father (no patient ID) who was also heterozygous for the mutation but did not have polycythemia. All three patients had hypersensitivity of erythroid progenitors to Epo.

PatientID: 2

KindredID: 1

Case: M, 10Y0M, Ukrainian

DiseaseAssertion: Asymptomatic

FamilyInfo: His sister (patient 1) also had polycythemia and was heterozygeous for the mutation. Mutation inherited from father. The father was not polycythemic, but his BFU-Es were hypersensitive to Epo.

CasePresentingHPOs: HP:0001901 (polycythemia)

CaseHPOFreeText: Patient had a hematocrit of 63%, erythropoietin level of 271 mIU/mL, and had hypersensitivity of erythroid progenitors to Epo.

CaseNotHPOs: N/A

CaseNotHPOFreeText: No tumor masses were detected by repeated CT scans of his abdomen or chest and by magnetic resonance imaging (MRI) of the head.

CasePreviousTesting: N/A

PreviouslyPublished: N/A

SupplementalData: N/A

Variant: p.D126Y(c.376G>T)

LegacyVariant: N/A

CaseProblemVariantFreeText: N/A

ClinVarID: 2230 https://www.ncbi.nlm.nih.gov/clinvar/variation/2230/

CAID: CA020319 http://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/allele?hgvsOrDescriptor=NM_000551.3%3Ac.376G%3ET

gnomAD: N/A

VariantEvidence: Patient was heterozygous for the mutation.

MutationType: missense_variant;transversion

CivicName: D126Y(c.376G>T)

MultipleGeneVariants: N/A