MedGen

Mandibulofacial dysostosis with microcephaly (MFDM) is characterized by malar and mandibular hypoplasia, microcephaly (congenital or postnatal onset), intellectual disability (mild, moderate, or severe), malformations of the external ear, and hearing loss that is typically conductive. Associated craniofacial malformations may include cleft palate, choanal atresia, zygomatic arch cleft (identified on cranial CT scan), and facial asymmetry. Other relatively common findings (present in 25%-35% of individuals) can include cardiac anomalies, thumb anomalies, esophageal atresia/tracheoesophageal fistula, short stature, spine anomalies, and epilepsy. [from GeneReviews]

Diamond-Blackfan anemia (DBA) is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50%, and growth deficiency in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia or no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma. [from GeneReviews]

Treacher Collins syndrome (TCS) is characterized by lower eyelid abnormalities, malar hypoplasia, downslanted palpebral fissures, and micro- or retrognathia due to symmetric hypoplasia of the zygomatic bones, maxilla, and mandible. External ear anomalies include absent, small, malformed, and/or posteriorly rotated ears and atresia or stenosis of the external auditory canals. About 40%-50% of individuals have conductive hearing loss attributed most commonly to malformation of the ossicles and hypoplasia of the middle ear cavities. Inner ear structures tend to be normal. Significant respiratory and feeding difficulties can be present in infancy. Other, less common abnormalities include cleft palate and unilateral or bilateral choanal stenosis or atresia. Typically, intellect is normal. [from GeneReviews]

A rare mandibulofacial dysostosis with the association with scalp alopecia and sparse eyebrows and eyelashes. Craniofacial dysmorphic features include zygomatic and mandibular dysplasia or hypoplasia, cleft palate, micrognathia, dental anomalies, auricular dysmorphism and eyelid anomalies among others. Patients may experience limited jaw mobility, glossoptosis, upper airway obstruction and conductive hearing loss. [from SNOMEDCT_US]

A very rare variant of acrofacial dysostosis with characteristics of mandibulofacial dysostosis and limb anomalies. It has been described in less than ten patients. The mandibulofacial dysostosis consists of retrognathism, complete or occult posterior cleft palate and anomalies of the external ears. Limb anomalies consist of split-foot deformity with syndactyly of some toes. The condition is transmitted as an autosomal dominant trait with variable penetrance and expressivity. [from SNOMEDCT_US]

The Catania type of acrofacial dysostosis is characterized by intrauterine growth retardation, short stature, microcephaly, intellectual disability, widow's peak, mandibulofacial dysostosis without cleft palate, ear anomalies, mild pre- and postaxial limb hypoplasia with brachydactyly, mild interdigital webbing, dental anomalies, and cryptorchidism and hypospadias in males (Opitz et al., 1993; Wulfsberg et al., 1996). [from OMIM]

Mandibulofacial dysostosis-macroblepharon-macrostomia syndrome is a rare developmental defect during embryogenesis disorder characterized by macroblepharon, ectropion, and facial dysmorphism which includes severe hypertelorism, downslanting palpebral fissures, posteriorly rotated ears, broad nasal bridge, long and smooth philtrum, and macrostomia with thin upper lip vermilion border. Other features may include large fontanelles, prominent metopic ridge, thick eyebrows, mild synophrys, increased density of upper eyelashes, anterverted nares, abnormal dentition and capillary hemangioma. [from ORDO]

Treacher Collins syndrome (TCS) is a disorder of craniofacial development. The features include downslanting palpebral fissures, coloboma of the eyelid, micrognathia, microtia and other deformity of the ears, hypoplastic zygomatic arches, and macrostomia. Conductive hearing loss and cleft palate are often present (summary by Dixon, 1996). Genetic Heterogeneity of Treacher Collins Syndrome Treacher Collins syndrome-2 (TCS2; 613717) is caused by mutation in the POLR1D gene (613715) on chromosome 13q12. Treacher Collins syndrome-3 (TCS3; 248390) is caused by mutation in the POLR1C gene (610060) on chromosome 6p21. Treacher Collins syndrome-4 (TCS4; 618939) is caused by mutation in the POLR1B gene (602000) on chromosome 2q14. [from OMIM]