Prevalence of specific and recurrent/founder pathogenic variants in BRCA genes in breast and ovarian cancer in North Africa

Background

Elucidation of specific and recurrent/founder pathogenic variants (PVs) in BRCA (BRCA1 and BRCA2) genes can make the genetic testing, for breast cancer (BC) and/or ovarian cancer (OC), affordable for developing nations.

Methods

To establish the knowledge about BRCA PVs and to determine the prevalence of the specific and recurrent/founder variants in BRCA genes in BC and/or OC women in North Africa, a systematic review was conducted in Morocco, Algeria, and Tunisia.

Results

Search of the databases yielded 25 relevant references, including eleven studies in Morocco, five in Algeria, and nine in Tunisia. Overall, 15 studies investigated both BRCA1 and BRCA2 genes, four studies examined the entire coding region of the BRCA1 gene, and six studies in which the analysis was limited to a few BRCA1 and/or BRCA2 exons. Overall, 76 PVs (44 in BRCA1 and32 in BRCA2) were identified in 196 BC and/or OC patients (129 BRCA1 and 67 BRCA2 carriers). Eighteen of the 76 (23.7%) PVs [10/44 (22.7%) in BRCA1 and 8/32 (25%) in BRCA2] were reported for the first time and considered to be novel PVs. Among those identified as unlikely to be of North African origin, the BRCA1 c.68_69del and BRCA1 c.5266dupC Jewish founder alleles and PVs that have been reported as recurrent/founder variants in European populations (ex: BRCA1 c.181T>G, BRCA1 c1016dupA). The most well characterized PVs are four in BRCA1 gene [c.211dupA (14.7%), c.798_799detTT (14%), c.5266dup (8.5%), c.5309G>T (7.8%), c.3279delC (4.7%)] and one in BRCA2 [c.1310_1313detAAGA (38.9%)]. The c.211dupA and c.5309G>T PVs were identified as specific founder variants in Tunisia and Morocco, accounting for 35.2% (19/54) and 20.4% (10/49) of total established BRCA1 PVs, respectively. c.798_799delTT variant was identified in 14% (18/129) of all BRCA1 North African carriers, suggesting a founder allele. A broad spectrum of recurrent variants including BRCA1 3279delC, BRCA1 c.5266dup and BRCA2 c.1310_1313detAAGA was detected in 42 patients. BRCA1 founder variants explain around 36.4% (47/129) of BC and outnumber BRCA2 founder variants by a ratio of ≈3:1.

Conclusions

Testing BC and/or OC patients for the panel of specific and recurrent/founder PVs might be the most cost-effective molecular diagnosis strategy.

[Mirror syndrome: literature review based on a case]

Le syndrome miroir ou syndrome de Ballantyne est une entité pathologique rare, définit par l´association d´une anasarque fœtale et d´un œdème maternel généralisé pouvant se compliquer d´une prééclampsie. L´objectif de ce travail est de mettre en exergue les particularités diagnostic et thérapeutique de cette entité clinique grave, qui, en dépit de sa rareté, ne doit pas être méconnu. Et ceux à travers la description d´un cas clinique d´une parturiente de 35 ans qui s´est présentée aux urgences, à 26 semaines d´aménorrhée, dans un tableau de syndrome miroir idiopathique dont l´évolution fut rapidement marquée par la survenue d´un décès in utéro puis régression de la symptomatologie clinico-biologique maternelle une fois la vacuité utérine obtenue. En effet, un traitement spécifique in utéro est vivement souhaitable. Quoique dans certains cas graves idiopathiques, seule l´obtention de la vacuité utérine permet l´amélioration du pronostic maternel voire fœtale.

[Epidemiological and economic aspects of chelating therapy in the therapeutic center of thalassemia in Morocco]

The study aims to give a general idea about the new experience of chelating drugs among beta-thalassemia patients. It is a declarative survey. It was done in the therapy center of Morocco. Statistics were done in the Laboratory of Biological Essays in Kenitra. All economic and pharmacological data were given by Novartis. Sample size was 89. The only treatment available now in the therapy center is deferiprone. 78% of patients attending the service regularly take deferiprone as treatment while 13% of them combine deferiprone and deferoxamine. Most of the patients take treatments regularly. Chelators have reduced mortality. Patients taking deferoxamine experienced injection site reactions. Most of ADR due to deferiprone were digestive. In conclusion, the main problem with chelators in Morocco is lack of accessibility to drugs (except for some patients insured or payant).