MedGen

Neuroferritinopathy is an adult-onset progressive movement disorder characterized by chorea or dystonia and speech and swallowing deficits. The movement disorder typically affects one or two limbs and progresses to become more generalized within 20 years of disease onset. When present, asymmetry in the movement abnormalities remains throughout the course of the disorder. Most individuals develop a characteristic orofacial action-specific dystonia related to speech that leads to dysarthrophonia. Frontalis overactivity and orolingual dyskinesia are common. Cognitive deficits and behavioral issues become major problems with time. [from GeneReviews]

Torsion dystonia-6 (DYT6) is an autosomal dominant movement disorder characterized by early involvement of craniofacial muscles with secondary generalization often involving the arms, and laryngeal dystonia that causes speech difficulties (review by Djarmati et al., 2009). Blanchard et al. (2011) provided a review of dystonia-6 and the THAP1 gene. [from OMIM]

Dystonia 16 is one of many forms of dystonia, which is a group of conditions characterized by involuntary movements, twisting (torsion) and tensing of various muscles, and unusual positioning of affected body parts. Dystonia 16 can appear at any age from infancy through adulthood, although it most often begins in childhood.

The signs and symptoms of dystonia 16 vary among people with the condition. In many affected individuals, the disorder first affects muscles in one or both arms or legs. Tensing (contraction) of the muscles often sets the affected limb in an abnormal position, which may be painful and can lead to difficulty performing tasks, such as walking. In others, muscles in the neck are affected first, causing the head to be pulled backward and positioned with the chin in the air (retrocollis).

In dystonia 16, muscles of the jaw, lips, and tongue are also commonly affected (oromandibular dystonia), causing difficulty opening and closing the mouth and problems with swallowing and speech. Speech can also be affected by involuntary tensing of the muscles that control the vocal cords (laryngeal dystonia), resulting in a quiet, breathy voice or an inability to speak clearly. Dystonia 16 gradually gets worse, eventually involving muscles in most parts of the body.

Some people with dystonia 16 develop a pattern of movement abnormalities known as parkinsonism. These abnormalities include unusually slow movement (bradykinesia), muscle rigidity, tremors, and an inability to hold the body upright and balanced (postural instability). In dystonia 16, parkinsonism is relatively mild if it develops at all.

The signs and symptoms of dystonia 16 usually do not get better when treated with drugs that are typically used for movement disorders. [from MedlinePlus Genetics]

KMT2B-related disorders include KMT2B-related dystonia (DYT-KMT2B), reported in 93% families, and KMT2B-related neurodevelopmental disorder (NDD) that is non-dystonic, reported in 7% of families. DYT-KMT2B is a complex childhood-onset progressive movement disorder (median age of onset: 6 years; range: 0-43 years) typically evolving from lower-limb focal dystonia into generalized dystonia with prominent cervical, cranial, and laryngeal involvement. Communication difficulties secondary to articulation difficulties (dysarthria) and low speech volume (hypophonia) are common. Bulbar dysfunction can lead to impaired swallowing with an increased risk of aspiration and need for gastrostomy tube placement in some. Most individuals have additional neurologic or systemic manifestations including intellectual disability (ID) / developmental delay (DD), other movement disorders (myoclonus, spasticity, tremor, ataxia, eye movement abnormalities), and neurobehavioral/psychiatric manifestations (e.g., attention-deficit/hyperactivity disorder, anxiety, depression, and obsessive-compulsive disorder.) Life expectancy is not known; however, individuals in the seventh decade of life have been reported. KMT2B-related NDD, sometimes described in family members of individuals with DYT-KMT2B, is characterized by DD and ID ranging from mild to severe. Additional findings can include bulbar dysfunction and neurobehavioral/psychiatric manifestations. Life expectancy is not known; to date, too few individuals have been reported. [from GeneReviews]

DYT-GNAL caused by a heterozygous GNAL pathogenic variant has been reported in more than 60 individuals to date. It is characterized by adult-onset isolated dystonia (i.e., no neurologic abnormalities other than tremor are evident on neurologic examination). The dystonia is most commonly focal and segmental, and rarely generalized. Dystonia is typically cervical in onset and commonly progresses to the cranial region (oromandibular/jaw, larynx, eyelids) and/or to one arm. Tremor reported in DYT-GNAL may be dystonic (i.e., occurring in a body part that shows at least minimal signs of dystonia) and may precede or follow the onset of dystonia. Intra- and interfamilial variability is considerable. DYT-GNAL caused by biallelic GNAL pathogenic variants, reported to date in two sibs from a consanguineous family, is characterized by mild intellectual disability and childhood-onset hypertonia that progresses to generalized dystonia. [from GeneReviews]

Dystonia-27 (DYT27) is an autosomal recessive neurologic disorder characterized by onset of segmental isolated dystonia mainly affecting the craniocervical region and upper limbs in the first 2 decades of life (summary by Zech et al., 2015). [from OMIM]

Myoclonic dystonia-26 (DYT26) is an autosomal dominant neurologic disorder characterized by onset of myoclonic jerks affecting the upper limbs in the first or second decade of life. The disorder is progressive, and patients later develop dystonia with predominant involvement of the craniocervical regions and sometimes the trunk and/or lower limbs. Dystonia dominates the clinical picture (summary by Mencacci et al., 2015). [from OMIM]

The Cincinnati type of acrofacial dysostosis is a ribosomopathy characterized by a spectrum of mandibulofacial dysostosis phenotypes, with or without extrafacial skeletal defects (Weaver et al., 2015). In addition, a significant number of neurologic abnormalities have been reported, ranging from mild delays to refractory epilepsy, as well as an increased incidence of congenital heart defects, primarily septal in nature (Smallwood et al., 2023). [from OMIM]

Dystonia-32 (DYT32) is an autosomal recessive neurologic disorder characterized by sustained or intermittent muscle contractions causing abnormal movements or posturing. The onset of symptoms is in adulthood, and the disorder is slowly progressive with eventual generalized involvement of the limbs, trunk, neck, and larynx, resulting in dysarthria and dysphagia. Brain imaging may show abnormalities in the basal ganglia. There are no additional neurologic signs or symptoms (summary by Monfrini et al., 2021). In a review of the pathogenesis of disorders with prominent dystonia, Monfrini et al. (2021) classified DYT32 as belonging to a group of neurologic disorders termed 'HOPS-associated neurologic disorders' (HOPSANDs), which are caused by mutations in genes encoding various components of the autophagic/endolysosomal system, including VPS11. [from OMIM]

Early-onset dystonia and/or spastic paraplegia (DYTSPG) is an autosomal dominant neurologic movement disorder characterized by phenotypic variability, even within the same family. Some patients have onset of progressive focal and generalized dystonia in the first decade, as young as infancy, whereas others develop progressive spastic paraplegia as adults, suggesting that age affects the phenotype. Some patients have manifestations of both disorders. Most patients have ambulation difficulties (Gilbert et al., 2009). Rare patients may show hypotonia and neurodevelopmental delay (Zech et al., 2022). [from OMIM]

Dystonia-21 (DYT21) is an autosomal dominant form of pure torsion dystonia, a movement disorder characterized by sustained muscle contractions causing twisting and repetitive movements and abnormal postures (summary by Norgren et al., 2011). [from OMIM]

Juvenile-onset dystonia-22 (DYT22JO) is an autosomal recessive disorder characterized by progressive, generalized dystonia associated with cognitive decline and cerebellar atrophy on brain imaging (Mencacci et al., 2021). [from OMIM]

A form of focal dystonia that affects the vocal cords, associated with involuntary contractions of the vocal cords causing interruptions of speech and affecting the voice quality and often leading to patterned, repeated breaks in speech. [from HPO]