Methylation of the glucocorticoid receptor gene (NR3C1) in dyads mother-child exposed to intimate partner violence in Cameroon

The glucocorticoid receptor (GR), which is encoded by the NR3C1 (Nuclear Receptor Subfamily 3 Group C Member 1) gene plays an important role in the modulation of the hypothalamic-pituitary-adrenal (HPA) axis activity by providing feedback regulation which allows termination of the stress response. Little is known about epigenetic programming at the level of NGFI-A putative binding site (CpG) of the NR3C1 exon 1F in dyads mother-child exposed to intimate partner violence (IPV) more specifically in an unstudied region such as the Sub-Saharan Africa where levels of violence are very high. This study seek to examine NR3C1 exon 1F methylation in response to IPV and possible association with cortisol concentration and mental health. We recruited 20 mother–child dyads exposed to IPV and a control group of 20 mother–child dyads. We administered self-reported questionnaires to measure mother’s mental health and collected saliva samples for cortisol dosage and bisulfite sequencing of DNA methylation.

Time Period:  9/1/2018 – 5/1/2022

Data Type:  clinical data

Sampling:  Convenient sampling

Data Source:   Original research
We recruited a total of 75 mother-child dyads with the help of the Association for the Fight against Domestic Violence (ALVF) a non-profit organisation based in Cameroon, which aids female victims of IPV. However, this epigenetic study was conducted on a subsample of 40 mother-infant dyads because in this pilot study we were eager to see if the epigenetic data collection and their analysis were possible in the Cameroonian context. The recruitment was done with the help of community agents of ALVF who performed a door-to-door sensitization and awareness campaign for our study. 

Collection Mode:  on-site questionnaire

Scales:  

Assessment of IPV

IPV was measured using the Revised Conflict Tactics Scale [CTS2; 37, 1996; French version by 38,1997]. This 78-item version explores violence between the mother and her partner in the past 12 months on 5 scales: negotiation skills (e.g. ‘I explained my side or suggested a compromise’), psychological abuse (e.g. ‘insulted, stomped out of room, or threatened to hit me’), physical abuse (e.g. ‘pushed, kicked, burned, scalded, or slapped me’), sexual abuse (e.g. ‘used force, used threats, to make me have sex’), and injuries (e.g. ‘felt pain, needed to see a doctor because of a fight’). The CTS2 is scored by adding the midpoints of the response categories chosen by the participant. The midpoints were 0 = 0 times, 1 = 1 time, 2 = 2 times, 4 = 3–5 times, 8 = 6–10 times, 15 = 11–20 times, and 25 = more than 20 times. Since there is no total score of the CTS2 and no validated cut-off score, we used the subscale scores, namely the scores for psychological abuse, physical abuse, sexual abuse, and injuries, and analyzed each of the subscales of the CTS2 separately. The global Cronbach’s alpha coefficient for this scale was 0.88. Looking at the subscales, we found a Cronbach’s alpha of .57 for psychological abuse, .71 for physical abuse, .50 for sexual abuse and .79 for injury. Mother mental health indicators Hospital Anxiety and Depression Scale [HADS; 39; French version by 40] was used to examine mothers’ current anxiety and depression symptoms. The HADS is composed of 14 items rated from zero to three, with seven questions related to anxiety and seven others related to depression. Two scores are obtained, with a minimum of zero and a maximum of 21. Higher scores indicate higher levels of anxiety and depression (Cronbach’s coefficient: anxiety subscale =.72 and depression subscale =.61).