Global developmental delay, and Waddling gait

Zebra body myopathy is a benign congenital myopathy, characterised by congenital hypotonia and weakness. Prevalence is unknown. Less than ten patients have been described so far. Muscle biopsy shows zebra bodies and other myopathic changes. Mutations of the alpha-skeletal actin (ACTA1) gene may be involved.

• Global developmental delay
• Elevated serum creatine phosphokinase
• Neonatal hypotonia
• Proximal muscle weakness
• Facial palsy

SOURCES: ORPHANET MENDELIAN

Autosomal recessive limb-girdle muscular dystrophy type 2P (LGMD2P) is a form of limb-girdle muscular dystrophy characterized by slowly-progressive, mainly proximal, muscle weakness presenting in early childhood (with difficulties walking and climbing stairs) and mild to severe intellectual disability. Additional manifestations reported include microcephaly, mild increase in thigh or calf muscles, and contractures of the ankles.

AUTOSOMAL RECESSIVE LIMB-GIRDLE MUSCULAR DYSTROPHY TYPE 2P Is also known as muscular dystrophy, limb-girdle, type 2p|muscular dystrophy, limb-girdle, autosomal recessive 16|muscular dystrophy-dystroglycanopathy, limb-girdle, dag1-related|lgmdr16|lgmd2p

• Intellectual disability
• Global developmental delay
• Muscle weakness
• Flexion contracture
• Delayed speech and language development

SOURCES: ORPHANET OMIM MENDELIAN

• Intellectual disability
• Global developmental delay
• Tremor
• Intellectual disability, severe
• Long philtrum

SOURCES: ORPHANET OMIM MENDELIAN

Megaconial-type congenital muscular dystrophy is an autosomal recessive disorder characterized by early-onset muscle wasting and mental retardation. Some patients develop fatal cardiomyopathy. Muscle biopsy shows peculiar enlarged mitochondria that are prevalent toward the periphery of the fibers but are sparse in the center (summary by Mitsuhashi et al., 2011).

MEGACONIAL CONGENITAL MUSCULAR DYSTROPHY Is also known as muscular dystrophy, congenital, with mitochondrial structural abnormalities|congenital megaconial myopathy|congenital muscular dystrophy due to phosphatidylcholine biosynthesis defect|congenital muscular dystrophy with mitochondrial structural abnormaliti

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

SOURCES: OMIM ORPHANET MESH MENDELIAN

Spastic paraplegia-47 is an autosomal recessive neurodegenerative disorder characterized by neonatal hypotonia that progresses to hypertonia and spasticity and severe mental retardation with poor or absent speech development (summary by Abou Jamra et al., 2011).

SPASTIC PARAPLEGIA 47, AUTOSOMAL RECESSIVE; SPG47 Is also known as cpsq5, formerly|cerebral palsy, spastic quadriplegic, 5, formerly

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

SOURCES: OMIM MENDELIAN

MDDGB6 is an autosomal recessive congenital muscular dystrophy with mental retardation and structural brain abnormalities (Longman et al., 2003). It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1 ), collectively known as 'dystroglycanopathies' (Mercuri et al., 2009).For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (OMIM ).

MUSCULAR DYSTROPHY-DYSTROGLYCANOPATHY (CONGENITAL WITH MENTAL RETARDATION), TYPE B, 6; MDDGB6 Is also known as mdc1d|muscular dystrophy, congenital, large-related|muscular dystrophy, congenital, type 1d

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

SOURCES: MESH ORPHANET OMIM MENDELIAN

MRD13 is an autosomal dominant form of mental retardation associated with variable neuronal migration defects resulting in cortical malformations. More variable features include early-onset seizures and mild dysmorphic features. Some patients may also show signs of peripheral neuropathy, such as abnormal gait, hyporeflexia, and foot deformities (summary by Willemsen et al., 2012 and Poirier et al., 2013).

MENTAL RETARDATION, AUTOSOMAL DOMINANT 13; MRD13 Is also known as mental retardation, autosomal dominant 13, with neuronal migration defects

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

SOURCES: OMIM MENDELIAN

Homocystinuria due to methylene tetrahydrofolate reductase (MTHFR) deficiency is a metabolic disorder characterised by neurological manifestations.

HOMOCYSTINURIA DUE TO METHYLENE TETRAHYDROFOLATE REDUCTASE DEFICIENCY Is also known as methylenetetrahydrofolate reductase deficiency|mthfr deficiency|methylene tetrahydrofolate reductase deficiency

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

SOURCES: OMIM ORPHANET MENDELIAN

Metaphyseal chondromatosis with D-2-hydroxyglutaric aciduria is an extremely rare genetic disorder characterized by the unique association of enchondromatosis with D-2 hydroxyglutaric aciduria (see these terms). Clinical features include enchondromatosis (with short stature, severe metaphyseal dysplasia and mild vertebral involvement), elevated levels of urinary 2-hydroxyglutaric acid and mild developmental delay.

METAPHYSEAL CHONDROMATOSIS WITH D-2-HYDROXYGLUTARIC ACIDURIA Is also known as spondyloenchondromatosis with d-2-hydroxyglutaric aciduria|metaphyseal enchondrodysplasia with 2-hydroxyglutaric aciduria|metaphyseal chondromatosis with d-2-hydroxyglutaric aciduria

• Global developmental delay
• Short stature
• Scoliosis
• Strabismus
• Depressed nasal bridge

SOURCES: ORPHANET OMIM MENDELIAN