Micrognathia, and Dysphagia

Lethal congenital contracture syndrome-7, an axoglial form of arthrogryposis multiplex congenita, is characterized by congenital distal joint contractures, polyhydramnios, reduced fetal movements, and severe motor paralysis leading to death early in the neonatal period (Laquerriere et al., 2014).For a general phenotypic description and a discussion of genetic heterogeneity of lethal congenital contracture syndrome, see LCCS1 (OMIM ).

• Generalized hypotonia
• Micrognathia
• Cleft palate
• Flexion contracture
• Areflexia

SOURCES: OMIM MENDELIAN

TRISMUS-PSEUDOCAMPTODACTYLY SYNDROME Is also known as distal arthrogryposis type 7|hecht-beals syndrome|mouth, inability to open completely, and short finger-flexor tendons|trismus-pseudocamptodactyly syndrome|hecht syndrome|dutch-kentucky syndrome

• Short stature
• Micrognathia
• Abnormal facial shape
• Ptosis
• Feeding difficulties

SOURCES: OMIM MESH ORPHANET 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 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 ).

• Generalized hypotonia
• Micrognathia
• Muscle weakness
• Ptosis
• Flexion contracture

SOURCES: OMIM 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

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

Spinal muscular atrophy with congenital bone fractures is an autosomal recessive severe neuromuscular disorder characterized by onset of severe hypotonia in utero. This results in congenital contractures, consistent with arthrogryposis multiplex congenita, and increased incidence of prenatal fracture of the long bones. Affected infants have difficulty breathing and feeding and often die in the first months or years of life (summary by Knierim et al., 2016). Genetic Heterogeneity of Spinal Muscular Atrophy With Congenital Bone FracturesSee also SMABF2 (OMIM ), caused by mutation in the ASCC1 gene (OMIM ) on chromosome 10q22.

• Global developmental delay
• Generalized hypotonia
• Hypertelorism
• Muscle weakness
• Flexion contracture

SOURCES: OMIM MENDELIAN

Myofibrillar myopathy-8 is an autosomal recessive myopathy characterized by childhood onset of slowly progressive proximal muscle weakness and atrophy resulting in increased falls, gait problems, and difficulty running or climbing stairs. Upper and lower limbs are affected, and some individuals develop distal muscle weakness and atrophy. Ambulation is generally preserved, and patients do not have significant respiratory compromise. Muscle biopsy shows a mix of myopathic features, including myofibrillar inclusions and sarcomeric disorganization (summary by O'Grady et al., 2016).For a general phenotypic description and a discussion of genetic heterogeneity of myofibrillar myopathy, see MFM1 (OMIM ).

• Generalized hypotonia
• Scoliosis
• Micrognathia
• Muscle weakness
• Ptosis

SOURCES: OMIM MENDELIAN

Osteogenesis imperfecta type XVIII (OI18) is characterized by congenital bowing of the long bones, wormian bones, blue sclerae, vertebral collapse, and multiple fractures in the first years of life (Doyard et al., 2018).

• Global developmental delay
• Generalized hypotonia
• Micrognathia
• Delayed speech and language development
• Motor delay

SOURCES: OMIM MENDELIAN

Intellectual disability, Birk-Barel type is a rare, genetic, syndromic intellectual disability characterized by congenital central hypotonia, developmental delay, moderate to severe intellectual disability and subtle dysmorphic features which evolve over time (dolichocephaly, myopathic facies, ptosis, short and broad philtrum, tented upper lip vermillion, palatal anomalies, mild micro- and/or retrognathia). Patients present reduced facial movements, lethargy, weak cry, transient neonatal hypoglycemia, severe feeding difficulties and failure to thrive. Dysphagia, particularly of solid food, asthenic body build, joint contractures and scoliosis are additional features.

INTELLECTUAL DISABILITY, BIRK-BAREL TYPE Is also known as intellectual disability-hypotonia-facial dysmorphism syndrome|birk-barel mental retardation dysmorphism syndrome|mental retardation with hypotonia and facial dysmorphism

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

SOURCES: MESH OMIM ORPHANET MENDELIAN

Childhood onset nemaline myopathy, or mild nemaline myopathy is a type of nemaline myopathy (NM; see this terms) characterized by distal muscle weakness, and sometimes slowness of muscle contraction.

CHILDHOOD-ONSET NEMALINE MYOPATHY Is also known as mild nemaline myopathy

• Generalized hypotonia
• Scoliosis
• Hypertelorism
• Micrognathia
• Ptosis

SOURCES: ORPHANET MENDELIAN