Low-set ears, and Optic atrophy

AICA-ribosiduria is an extremely severe inborn error of purine biosynthesis characterized clinically in the single reported case to date by profound intellectual deficit, epilepsy, dysmorphic features of the knees, elbows, and shoulders and congenital blindness.

AICA-RIBOSIDURIA Is also known as aica-ribosuria due to atic deficiency|5-amino-4-imidazole carboxamide ribosiduria|atic deficiency

• Intellectual disability
• Seizures
• Generalized hypotonia
• Muscular hypotonia
• Low-set ears

SOURCES: OMIM MESH ORPHANET MENDELIAN

Permanent neonatal diabetes mellitus-pancreatic and cerebellar agenesis syndrome is characterized by neonatal diabetes mellitus associated with cerebellar and/or pancreatic agenesis.

PERMANENT NEONATAL DIABETES MELLITUS-PANCREATIC AND CEREBELLAR AGENESIS SYNDROME Is also known as pancreatic and cerebellar agenesis|diabetes mellitus, permanent neonatal, with cerebellar agenesis

• Seizures
• Microcephaly
• Growth delay
• Failure to thrive
• Abnormal facial shape

SOURCES: OMIM MESH ORPHANET MENDELIAN

Hypomyelinating leukodystrophy-14 is an autosomal recessive neurodevelopmental disorder characterized by hypotonia, almost complete lack of motor or cognitive skills, and absent language development. Additional features include spasticity and intractable seizures; many patients also have perceptive hearing loss and/or blindness. Most patients require tube feeding or ventilatory support, and most die in the first years of life. Brain imaging shows hypomyelination, small caudate and putamen, and cerebral and cerebellar atrophy (summary by Hamilton et al., 2017).For a general phenotypic description and a discussion of genetic heterogeneity of hypomyelinating leukodystrophy, see {312080}.

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

SOURCES: OMIM MENDELIAN

Neonatal adrenoleukodystrophy (NALD) is the variant of intermediate severity of the PBD-Zellweger syndrome spectrum (PBD-ZSS; see this term), charcterized by hypotonia, leukodystrophy, and vision and sensorineural hearing deficiencies. Phenotypic overlap is seen between NALD and infantile Refsum disease (IRD) (see this term).

NEONATAL ADRENOLEUKODYSTROPHY Is also known as nald

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

SOURCES: OMIM ORPHANET MENDELIAN

NMIHBA is a severe, autosomal recessive, neurodevelopmental, and neurodegenerative disorder characterized by global developmental delay apparent from infancy and profound intellectual disability. Affected individuals have microcephaly with accompanying dysmorphic features, truncal hypotonia, peripheral spasticity, and lack of independent ambulation or speech acquisition. Brain imaging shows variable abnormalities, including cortical atrophy, thin corpus callosum, cerebellar hypoplasia, and delayed myelination (summary by Zollo et al., 2017).

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

SOURCES: OMIM MENDELIAN

Pontocerebellar hypoplasia type 3 (PCH3), also known as cerebellar atrophy with progressive microcephaly (CLAM) is a rare form of pontocerebellar hypoplasia (see this term) with autosomal recessive transmission characterized neonatally by hypotonia and impaired swallowing and from infancy onward by seizures, optic atrophy and short stature, but none of the clinical findings are specific for PCH3.

PONTOCEREBELLAR HYPOPLASIA TYPE 3 Is also known as pch without dyskinesia|cerebellar atrophy with progressive microcephaly|clam|pch with optic atrophy|pch3

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

SOURCES: OMIM MESH ORPHANET MENDELIAN

JABELS is an autosomal recessive neurodevelopmental disorder characterized by developmental delay and intellectual disability with additional variable features. Patients have onset of symptoms in infancy, but the severity is highly variable. Some patients have social interaction and learn to walk but have an ataxic gait and abnormal movements, such as tremor or dystonia, whereas others do not achieve any motor control and are unable to speak. Additional features may include retinal anomalies, visual impairment, microcephaly, abnormal foot or hand posturing, and kyphoscoliosis; some patients have dysmorphic facial features or seizures. Brain imaging typically shows cerebellar atrophy and hypoplasia of the corpus callosum (summary by Jaberi et al., 2016 and Bertoli-Avella et al., 2018).

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

SOURCES: OMIM MENDELIAN

Neurodevelopmental disorder with or without anomalies of the brain, eye, or heart is an autosomal dominant syndrome characterized by onset in infancy of developmental delay, intellectual disability, and behavioral disorders, such as autism spectrum disorders. About half of patients have additional abnormalities, most commonly involving the eye, heart, and genitourinary system. The phenotype is reminiscent of that observed in patients with 1p36 deletion syndrome (OMIM ); RERE is located in the proximal 1p36 critical region (summary by Fregeau et al., 2016).

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

SOURCES: OMIM MENDELIAN

Meckel syndrome (MKS) is a rare, lethal, genetic, multiple congenital anomaly disorder characterized by the triad of brain malformation (mainly occipital encephalocele), large polycystic kidneys, and polydactyly, as well as associated abnormalities that may include cleft lip/palate, cardiac and genital anomalies, central nervous system (CNS) malformations, liver fibrosis, and bone dysplasia.

MECKEL SYNDROME Is also known as meckel-gruber syndrome

• Microcephaly
• Hypertelorism
• Micrognathia
• Cleft palate
• Cataract

SOURCES: ORPHANET MENDELIAN

Lethal neonatal rigidity and multifocal seizure syndrome is a severe autosomal recessive epileptic encephalopathy characterized by onset of rigidity and intractable seizures at or soon after birth. Affected infants achieve no developmental milestones and die within the first months or years of life (summary by Saitsu et al., 2014).

LETHAL NEONATAL SPASTICITY-EPILEPTIC ENCEPHALOPATHY SYNDROME Is also known as lethal neonatal rigidity-multifocal seizure syndrome

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

SOURCES: OMIM ORPHANET MENDELIAN