Heterozygous mutations in the glucocerebrosidase gene (GBA) have been shown to be an important genetic risk factor for Parkinson\'s disease (PD) worldwide. However, the penetrance of GBA heterozygote for L444P, the common mutation for Asian population, is not known in older Chinese people.
To assess the conversion rate to PD in identified carriers of GBA L444P/R mutations in Chinese community-dwelling older adults.
The GBA gene was sequenced for mutations at position 444 in 8405 people older than 55 years who participated in the Beijing Longitudinal Study on Aging II cohort. Nine subjects were identified as heterozygous carriers of GBA L444P or L444R mutations at baseline and clinically followed up from 2009 to 2019 to investigate their PD conversion, motor and nonmotor symptoms, and change of vesicular monoamine transporter type 2 using tracer of [18 F]9-fluoropropyl-(+)-dihydrotetrabenazine (18 F-DTBZ, also known as 18 F-AV-133).
Eight heterozygous GBA L444P and 1 L444R mutation carriers were identified without PD at baseline, and none of them developed clinical parkinsonism after a 10-year follow-up.
Although GBA mutations may lead to an earlier onset PD, the majority of GBA L444P heterozygotes in older adults may not convert to PD. Further studies are warranted to identify factors that modify the risk of conversion. © 2020 International Parkinson and Movement Disorder Society.

To investigate the incidence of thrombotic events in patients heterozygous for FXII deficiency during a long observation period.
103 heterozygotes for FXII deficiency, 49 female and 54 male were followed for 19.6 years (range 5-32 years). As controls 103 unaffected family members of same sex and similar age (±5 years) were enrolled. The thrombotic end points were: myocardial infarction, deep vein thrombosis and ischemic stroke. The mean Factor XII level in the heterozygotes was 48.5%: range (35-60%) that of control was 96.5% (range 70-155%). The heterozygotes showed one myocardial infarction, two deep vein thromboses and no ischemic stroke. The unaffected family members observed 2 myocardial infarctions, one deep vein thrombosis and one ischemic stroke. There were seven deliveries (five women) among the heterozygotes and six (five women) among the controls. Furthermore, four and five surgical procedures were carried out in the patient and in the control group, respectively. Immobilization times for surgical procedures or pregnancies were 50 days and 57 days for the heterozygotes and the unaffected family members, respectively. Heterozygotes for FXII deficiency did not show an increased incidence of thrombotic events as compared with unaffected family members during a long follow up.

At the time of this study, there were five known patients with Wilson disease (WD) in Iceland. The mutation, a 7-bp deletion in exon 7 on chromosome 13 for WD, is only known in Iceland. In twenty healthy Icelandic heterozygotes for WD and their age- and gender-matched controls, copper concentration in plasma, ceruloplasmin (CP) concentration, CP oxidative activity and CP-specific oxidative activity in serum and superoxide dismutase (SOD1) activity in erythrocytes were determined. The same determinations were done on the five WD patients. There was no significant difference in these parameters between the heterozygotes and the controls, although an inclination toward lower CP determinations and higher SOD1 activity in the heterozygotes was noted. As expected the WD patients were low on the copper and CP parameters, but their SOD1 activity was within the upper normal range. In conclusion, the CP parameters and SOD1 activity are within the normal range in Icelandic heterozygotes for WD, although with a trend toward mild dyshomeostasis. This may indicate subclinical copper retention in the heterozygotes, but a bigger study group is needed to confirm this.