Micrognathia, and Neurological speech impairment

• Intellectual disability
• Global developmental delay
• Microcephaly
• Hypertelorism
• Micrognathia

SOURCES: OMIM MENDELIAN

Orofaciodigital syndrome type 14 is a rare subtype of orofaciodigital syndrome, with autosomal recessive inheritance and C2CD3 mutations, characterized by severe microcephaly, trigonocephaly, severe intellectual disability and micropenis, in addition to oral, facial and digital malformations (gingival frenulae, lingual hamartomas, cleft/lobulated tongue, cleft palate, telecanthus, up-slanting palpebral fissures, microretrognathia, postaxial polydactyly of hands and duplication of hallux). Corpus callosum agenesis and vermis hypoplasia with molar tooth sign, on brain imaging, are also associated.

OROFACIODIGITAL SYNDROME TYPE 14 Is also known as oral-facial-digital syndrome type 14|ofd14|microcephaly-cerebral malformation-orofaciodigital syndrome

• Intellectual disability
• Microcephaly
• Abnormal facial shape
• Cleft palate
• Hypoplasia of the corpus callosum

SOURCES: OMIM ORPHANET MENDELIAN

Early infantile epileptic encephalopathy-64 is a neurodevelopmental disorder characterized by onset of seizures usually in the first year of life and associated with intellectual disability, poor motor development, and poor or absent speech. Additional features include hypotonia, abnormal movements, and nonspecific dysmorphic features. The severity is variable: some patients are unable to speak, walk, or interact with others as late as the teenage years, whereas others may have some comprehension (summary by Straub et al., 2018).For a general phenotypic description and a discussion of genetic heterogeneity of EIEE, see EIEE1 (OMIM ).

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Microcephaly

SOURCES: OMIM MENDELIAN

Microcephaly-2 with or without cortical malformations is an autosomal recessive neurodevelopmental disorder showing phenotypic variability. Classically, primary microcephaly is a clinical diagnosis made when an individual has a head circumference more than 3 standard deviations (SD) below the age- and sex-matched population mean, and mental retardation with no other associated malformations and with no apparent etiology (Hofman, 1984). Patients with WDR62 mutations have head circumferences ranging from low-normal to severe (-9.8 SD), and most patients with brain scans have shown various types of cortical malformations. All have delayed psychomotor development; seizures are variable (summary by Yu et al., 2010).For a general phenotypic description and a discussion of genetic heterogeneity of primary microcephaly, see MCPH1 (OMIM ).

• Intellectual disability
• Seizures
• Global developmental delay
• Microcephaly
• Growth delay

SOURCES: OMIM MESH MENDELIAN

HCFP3 is an autosomal recessive congenital cranial dysinnervation disorder characterized by isolated dysfunction of the seventh cranial nerve resulting in facial palsy. Additional features may include orofacial anomalies, such as smooth philtrum, lagophthalmos, swallowing difficulties, and dysarthria, as well as hearing loss. There is some phenotypic overlap with Moebius syndrome (see, e.g., {157900}), but patients with HCFP usually retain full eye motility or have esotropia without paralysis of the sixth cranial nerve (summary by Vogel et al., 2016).For a phenotypic description and a discussion of genetic heterogeneity of hereditary congenital facial paresis, see {601471}.

• Hearing impairment
• Micrognathia
• Strabismus
• Sensorineural hearing impairment
• Abnormal facial shape

SOURCES: OMIM MENDELIAN

• Seizures
• Global developmental delay
• Short stature
• Microcephaly
• Growth delay

SOURCES: OMIM MENDELIAN

Fast-channel congenital myasthenic syndrome (FCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor (AChR) channel, specifically from abnormally brief opening and activity of the channel, with a rapid decay in endplate current and a failure to reach the threshold for depolarization. Treatment with pyridostigmine or amifampridine may be helpful; quinine, quinidine, and fluoxetine should be avoided (summary by Sine et al., 2003 and Engel et al., 2015).For a discussion of genetic heterogeneity of CMS, see CMS1A (OMIM ).

• Scoliosis
• Micrognathia
• Muscle weakness
• Ptosis
• High palate

SOURCES: OMIM MENDELIAN

Periventricular nodular heterotopia-7 is a neurologic disorder characterized by abnormal neuronal migration during brain development resulting in delayed psychomotor development and intellectual disability; some patients may develop seizures. Other features include cleft palate and 2-3 toe syndactyly (summary by Broix et al., 2016).For a phenotypic description and a discussion of genetic heterogeneity of periventricular heterotopia, see {300049}.

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment

SOURCES: OMIM MENDELIAN

MRXSB is an X-linked dominant neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability with behavioral abnormalities, and dysmorphic facial features. Additional variable features include musculoskeletal abnormalities, seizures, acquired microcephaly, and feeding problems with poor overall growth. Only females are affected (summary by Bain et al., 2016).

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: OMIM MENDELIAN

CLIFAHDD is a congenital disorder characterized by congenital contractures of the limbs and face, resulting in characteristic facial features, hypotonia, and variable degrees of developmental delay. All reported cases have occurred de novo (summary by Chong et al., 2015).

• Seizures
• Global developmental delay
• Generalized hypotonia
• Scoliosis
• Micrognathia

SOURCES: OMIM MENDELIAN