Case1873(W.C.) Male, 37yo report, Irish
CasePresentingHPOs HP:0002625, HP:0000766, HP:0002942, HP:0006682, HP:0005625, HP:0002353
(Deep vein thrombosis, Sternal anomaly, Thoracic kyphosis, Ventricular extrasystoles, Osteoporosis of vertebrae, EEG abnormality)
HPOsFreeText Patient had single episode of deep vein thrombosis of left leg at 30yo. No further clinical sequelae related to homocystinuria.
(PMID: 20329304): Patient was born normally at 36wks gestation weighing 2.9kg. By 9 and half years old he was well developed and nourished, mentally normal at IQ 93. He did have pronounced malar flush, some grey hair of normal texture, slightly depressed sternum, mild kyphosis of upper thoracic spine. Exam of major systems was normal save for occasional ventricular extrasystole. Roengenogram showed marked osteoporosis of spine, but normal long bones. EEG showed non-specific diffuse abnormality.
CaseNotHPOs HP:0001083
(Lens dislocation)
NotHPOsFreeText lenses were found to not be displaced upon exam at 9 and a half years old.
CasePreviousTesting Plasma homocysteine was 450μM pretreatment. Pyroxidine treatment reduced those levels to trace amounts. In patient fibroblasts, no CBS protein was detect on Western blot and CBS assay detected no activity. (PMID: 20329304): "Full hemogram, routine urine analysis, liver function tests, serum ion and iron-binding capacity, plasma magnesium, serum calcium, inorganic phosphate, fasting blood sugars, blood urea nitrogen, and bone marrow examination were all normal". Heavy homocysteine spot shown on chromatogram of urinary amino acids.
CaseMethod1 PCR
CaseMethod2 Sanger
CaseGenotypingMethod Created a bacteria expression system in E.coli by substituting one of three fragments of (PCR amplified)patient cDNA into WT CBS sequence already subcloned in expression plasmids. Bacteria were screened based on which ones did not have CBS activity. Those that did not have activity were thought to have LOF variants in CBS. Plasmids containing the inactivating fragments, one cut with NcoI/XmaI and another cut with Bpu1102/BstX, were sequenced.
Variant 1. NM_000071.2:c.715G>A (p.Glu239Lys),
- NM_000071.2:c.233C>G (p.Pro78Arg);3. NM_000071.2:c.306G>C (p.Lys102Asn) - 2&3 in cis, compound heterozygous
ClinVar 1. n/a, 2. 188988;3. 188989
CAID 1. CA410600501
gnomAD 1. not in gnomAD, 2. MAF=0.0001631(Other), no homozygotes, 3. MAF=0.0001630(Other), no homozygotes
CaseAddInfo Mother had edema of both legs with no other features of pre-eclampsia during the last six weeks of pregnancy.
CasePMIDs 20329304