Monogenic hearing loss
Gene: TBX1
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Phenotypes
#187500:Tetralogy of Fallot[Tetralogy of Fallot; Preauricular pits; Fifth finger clinodactyly; Broad forehead; Prominent eyes; Sib recurrence risk of 1% for tetralogy and 2% for any congenital heart defect]; #188400:DiGeorge syndrome[Short stature (20% of adults); Obesity (35% of adults); Micrognathia; Low-set earsAbnormal folded pinnaMiddle ear abnormalitiesHearing deficits (28% of adults); Posterior embryotoxonTortuous retinal vasculatureHypertelorismShort palpebral fissuresEyelid hoodingAmblyopiaStrabismus (15% of adults)ExotropiaEsophoriaSclerocorneaAccommodative esotropiaComplicated strabismus; Blunted noseShort philtrum; High arched palateCleft palateBifid uvula; Cardiovascular malformations (26% of adults)Tetralogy of FallotTruncus arteriosusInterrupted aortic archRight aortic archVentricular septal defect; Patent ductus arteriosus; Umbilical herniaFemoral hernia; Cholelithiasis (19% of adults); Inguinal hernia; Scoliosis (47% of adults); Severe acne (23% of adults)Seborrhea (35% of adults); Mild to moderate learning difficultiesDelayed psychomotor developmentLate-onset speech developmentTetanySeizures (40%); Attention deficit disorderSchizophrenia (22% of adults)Bipolar disorder; Hypernasal speech; Parathyroid hypoplasiaParathyroid absenceThymic hypoplasiaThymic aplasiaAccessory thyroid tissueHypothyroidism (20% of adults); Immune defect due to a T cell deficitSusceptibility to infection; Neonatal hypocalcemiaHypocalcemia (64% of adults)T-cell deficit85-90% DGS patients have deletion of 22q11.2Other cytogenic abnormalities have been associated with DGS phenotype including monosomy 10p13, 11p13, and 4q21]; #192430:Velocardiofacial syndrome[Short stature; Microcephaly; LongPierre Robin syndromeRetrognathia; Minor auricular anomalies; Narrow palpebral fissuresSmall optic discsTortuous retinal vesselsPosterior embryotoxon; Square nasal rootDecreased nasopharyngeal lymphoid tissueProminent tubular noseHypoplastic nasal alaeBulbous nasal tip; Cleft palateVelopharyngeal insufficiencySmall open mouthPharyngeal hypotonia; Congenital abnormality in 85%Ventricular septal defectTetralogy of Fallot; Right aortic archAberrant left subclavianInternal carotid artery abnormalities; Primary pulmonary dysgenesis, unilateral (reported in 2 unrelated patients); Inguinal herniaUmbilical hernia; Slender hands and digits; Learning disabilityMental retardation; Blunt or inappropriate affectPsychotic illnessParanoiaAutistic featuresAggressionMood swings; Nasal voice; Neonatal hypocalcemia, rare; Frequent infections T-lymphocyte dysfunction, rare; Monosomy for 22q11]; #217095:Conotruncal anomaly face syndrome[<omim version=1.0><clinicalSynopsisList>]
Publications
TBX1 was added to Congenital hearing impairment (Profound/Severe)panel. Sources: Expert