[BCL11B associated disorder a case report in Mexican population. Case report].

Background: BCL11B variants are associated with intellectual developmental disorder with dysmorphic facies, speech delay, and T-cell abnormalities (IDDSFTA) (OMIN 618092). The clinical features include neurodevelopmental disorders (psychomotor delay, intellectual disability, language delay, autism spectrum features), facial dysmorphisms, immunological manifestations (asthma, allergies and T cells decrease). The aim is to present a IDDSFTA case in Mexican population with a probably pathogenic variant that has not been reported before and to compare it with literature cases.

Clinic case: A 4-years-old male presents neurodevelopmental and language delay, healthy parents, non-consanguineous. He presents incomprehensible language, joint attention, plagiocephaly, bilateral epicanthus, short palpebral fissures, prominent tip nose, long and flat philtrum, Likert scale 4, thin lips, small mouth, dental crowding, hypodontia, borderline set ears, small nipples and teletelia. WES test reported a BCL11B gene, probably a pathogenic variant.

Conclusions: In line with the information available, the detected variant has not been described before in literature; it is the first case reported of this pathology in the Mexican population. Patient's clinical features are IDDSFTA-like reported, which supports that this probable pathogenic variant is the etiology of the phenotype in our patient.