Global developmental delay (GDD) and intellectual disability (ID) refer to deficits in cognitive and adaptive functioning that arise during the developmental period. GDD/ID is often accompanied by complex developmental abnormalities, with congenital craniofacial malformations being among the most common, such as craniosynostosis, cleft lip and palate, and congenital tooth agenesis. However, the underlying mechanisms of GDD/ID associated with congenital craniofacial malformations remain unclear. With the increasing number of reported genetic syndromes, genetic factors are emerging as key contributors to the concurrent abnormalities in brain and craniofacial development. Studies have identified Wnt, SHH, FGF, and BMP as classical regulatory molecules in craniofacial development, and their roles have also been closely linked to various stages of brain development. This review focuses on the regulatory roles of Wnt, SHH, FGF, and BMP signaling pathways in brain and craniofacial development, as well as the pathogenic mechanisms underlying their association with GDD/ID and craniofacial malformations. The aim is to provide new insights into the etiology of GDD/ID combined with congenital craniofacial malformations.
Humans ; Craniofacial Abnormalities/complications* ; Signal Transduction ; Developmental Disabilities/metabolism* ; Intellectual Disability/complications* ; Animals ; Hedgehog Proteins/genetics* ; Fibroblast Growth Factors/genetics*

OBJECTIVE: To explore the genetic basis for a child with succinate semialdehyde dehydrogenase deficiency. METHODS: Peripheral blood samples of the proband and his parents were collected and subjected to Sanger sequencing. High-throughput sequencing was used to verify the gene variants. Bioinformatic software was used to analyze the pathogenicity of the variant sites. RESULTS: Sanger sequencing showed that the proband carried a homozygous c.1529C>T (p.S510F) variant of the ALDH5A1 gene, for which his mother was a carrier. The same variant was not detected in his father. However, high-throughput sequencing revealed that the child and his father both had a deletion of ALDH5A1 gene fragment (chr6: 24 403 265-24 566 986). CONCLUSION The c.1529C>T variant of the ALDH5A1 gene and deletion of ALDH5A1 gene fragment probably underlay the disease in the child. High-throughput sequencing can detect site variation as well as deletion of gene fragment, which has enabled genetic diagnosis and counseling for the family.
Amino Acid Metabolism, Inborn Errors/genetics* ; Child ; Developmental Disabilities ; Humans ; Infant ; Mutation ; Succinate-Semialdehyde Dehydrogenase/genetics*

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive hereditary disease and is a congenital metabolic disorder of neurotransmitter biosynthesis. It is mainly manifested as hypotonia, oculogyric crisis, autonomic dysfunction, and developmental delay. This article reports a boy manifested as delayed motor development, hypotonia, and oculogyric crisis. Gene screening for metabolic disorders revealed new compound heterozygous mutations, c.1063dupA (p.I355fs) and c.250A>C (p.S84R), in the exon of DDC gene. The boy had a significant increase in 3-O-methyldopa as measured by dried blood spot. Therefore, he was diagnosed with AADC deficiency. After treatment with the dopamine receptor agonist pramipexole dihydrochloride, the catechol-O-methyltransferase inhibitor entacapone, and vitamin B6, the boy showed mild improvements in hypotonia, blepharoptosis, and oculogyric crisis. Clinical physicians should enhance their ability for identifying AADC deficiency, so as to facilitate early diagnosis and treatment of this disorder. Genetic counseling for birth health and prenatal diagnosis should be performed for parents in need.
Amino Acid Metabolism, Inborn Errors ; complications ; Aromatic-L-Amino-Acid Decarboxylases ; deficiency ; Developmental Disabilities ; etiology ; Feeding and Eating Disorders ; etiology ; Humans ; Infant ; Male ; Nystagmus, Pathologic ; etiology

OBJECTIVETo detect potential mutation in a Chinese family affected with succinic semialdehyde dehydrogenase deficiency.

METHODSGenomic DNA was extracted from the peripheral blood samples of the proband, her family members and 100 healthy controls. All exons and flanking intronic regions of the ALDH5A1 gene were amplified by PCR and subjected to direct sequencing.

RESULTSThe proband was found to have compound heterozygous mutations of the ALDH5A1 gene, namely c.398_399delAA (p.N134X) and c.638G>T (p.R213L), for which her parents were both heterozygous carriers. The same mutations were not found among the 100 healthy controls.

CONCLUSIONThe novel mutations of the ALDH5A1 gene probably underlie the pathogenesis of the disease in the infant, which also enriched the mutation spectrum of the ALDH5A1 gene.

Amino Acid Metabolism, Inborn Errors ; ethnology ; genetics ; Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; DNA Mutational Analysis ; methods ; Developmental Disabilities ; ethnology ; genetics ; Exons ; genetics ; Family Health ; Female ; Heterozygote ; Humans ; Infant ; Introns ; genetics ; Male ; Mutation ; Sequence Homology, Amino Acid ; Succinate-Semialdehyde Dehydrogenase ; deficiency ; genetics

OBJECTIVETo explore the value of urine gas chromatography-mass spectrometry (GC-MS) in the screening of children at risk of inherited metabolic diseases (IMD), and to identify the disease spectrum of IMD and the clinical characteristics of children with IMD.

METHODSThe clinical data of 15 851 children at risk of IMD who underwent urine GC-MS in the Tianjin Children's Hospital between February 2012 and December 2016 were retrospectively analyzed.

RESULTSIn the 15 851 children, 5 793 (36.55%) were detected to have metabolic disorders. A total of 117 (0.74%) children were confirmed to have IMD, including 77 cases of methylmalonic acidemia (65.8%). The clinical manifestations of confirmed cases in the neonatal period mainly included jaundice, metabolic acidosis, abnormal muscular tension, feeding difficulty, poor response, and lethargy or coma. The clinical manifestations of confirmed cases in the non-neonatal period mainly included delayed mental and motor development, metabolic acidosis, convulsion, recurrent vomiting, and anemia.

CONCLUSIONSGC-MS is an effective method for the screening for IMD in children at risk. Methylmalonic acidemia is the most common IMD. The clinical manifestations of IMD are different between the confirmed cases in the neonatal and non-neonatal periods.

Acidosis ; etiology ; Adolescent ; Amino Acid Metabolism, Inborn Errors ; complications ; diagnosis ; Child ; Child, Preschool ; Developmental Disabilities ; etiology ; Female ; Gas Chromatography-Mass Spectrometry ; Humans ; Infant ; Infant, Newborn ; Male ; Metabolism, Inborn Errors ; complications ; diagnosis ; Retrospective Studies ; Risk

A one-year-old girl visited the hospital due to limb torsion and developmental regression for one month after hand, foot and mouth disease. At the age of 11 months, she visited a local hospital due to fever for 5 days and skin rash with frequent convulsions for 2 days and was diagnosed with severe hand, foot and mouth disease, viral encephalitis, and status epilepticus. Brain MRI revealed symmetric abnormal signals in the bilateral basal ganglia, bilateral thalamus, cerebral peduncle, bilateral cortex, and hippocampus. She was given immunoglobulin, antiviral drugs, and anticonvulsant drugs for 2 weeks, and the effect was poor. Blood and urine screening for inherited metabolic diseases were performed to clarify the etiology. The analysis of urine organic acids showed significant increases in glutaric acid and 3-hydroxyglutaric acid, which suggested glutaric aciduria type 1, but her blood glutarylcarnitine was normal, and free carnitine significantly decreased. After the treatment with low-lysine diets, L-carnitine, and baclofen for 1 month, the patient showed a significant improvement in symptoms. Hand, foot and mouth disease is a common viral infectious disease in children, and children with underlying diseases such as inherited metabolic diseases and immunodeficiency may experience serious complications. For children with hand, foot and mouth disease and unexplained encephalopathy, inherited metabolic diseases should be considered.
Amino Acid Metabolism, Inborn Errors ; etiology ; Brain Diseases, Metabolic ; etiology ; Developmental Disabilities ; etiology ; Female ; Glutaryl-CoA Dehydrogenase ; deficiency ; Hand, Foot and Mouth Disease ; complications ; Humans ; Infant ; Torsion Abnormality ; etiology

Global developmental delay (GDD) is a relatively common early-onset chronic neurological condition, which may have prenatal, perinatal, postnatal, or undetermined causes. Family history, physical and neurological examinations, and detailed history of environmental risk factors might suggest a specific disease. However, diagnostic laboratory tests, brain imaging, and other evidence-based evaluations are necessary in most cases to elucidate the causes. Diagnosis of GDD has recently improved because of remarkable advances in genetic technology, but this is an exhaustive and expensive evaluation that may not lead to therapeutic benefits in the majority of GDD patients. Inborn metabolic errors are one of the main targets for the treatment of GDD, although only a small proportion of GDD patients have this type of error. Nevertheless, diagnosis is often challenging because the phenotypes of many genetic or metabolic diseases often overlap, and their clinical spectra are much broader than currently known. Appropriate and cost-effective strategies including up-to-date information for the early identification of the "treatable" causes of GDD are needed for the development of well-timed therapeutic applications with the potential to improve neurodevelopmental outcomes.
Child* ; Developmental Disabilities ; Diagnosis ; Humans ; Metabolic Diseases ; Metabolism ; Neuroimaging ; Neurologic Examination ; Phenotype ; Risk Factors

OBJECTIVETo detect potential mutation in ALDH5A1 gene for a family affected with succinic semialdehyde dehydrogenase deficiency diagnosed by clinical inspection and urine screening.

METHODSPolymerase chain reaction and direct DNA sequencing were carried out for the affected child and her parents. Suspected ALDH5A1 gene mutations were verified in 100 healthy controls to exclude polymorphisms.

RESULTSThe child was found to have carried 2 heterozygous missense mutations in the coding region of ALDH5A1 gene, namely c.527G>A and c.691G>A, for which her mother and father were respectively heterozygotes. The same mutations were not detected in 100 healthy controls. The child was also found to have carried two previously described polymorphisms including a heterozygous c.545C>T(derived from her father) and a homozygous c.538C>T(derived from her mother).

CONCLUSIONMissense mutations of c.527G>A and c.691G>A in the ALDH5A1 gene are responsible for the pathogenesis of the disease in this family.

Adult ; Amino Acid Metabolism, Inborn Errors ; enzymology ; ethnology ; genetics ; Amino Acid Sequence ; Animals ; Asian Continental Ancestry Group ; ethnology ; genetics ; Base Sequence ; Child, Preschool ; China ; ethnology ; Developmental Disabilities ; Female ; Heterozygote ; Humans ; Male ; Molecular Sequence Data ; Mutation, Missense ; Pedigree ; Polymorphism, Genetic ; Succinate-Semialdehyde Dehydrogenase ; deficiency ; genetics

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder. This paper reports three cases of SSADH deficiency in infants. The infants developed the symptoms including developmental delay, intellectual disability, hypotonia, hyporeflexia and seizures. The electroencephalogram (EEG) showed background slowing and focal spike discharges in all of 3 patients. Head magnetic resonance imaging (MRI) demonstrated abnormalities in 2 patients, including basal ganglia damage and increased T2-weighted signal in bilateral cerebral peduncles. Urinary organic acid analysis with gas chromatography-mass spectrometry (GC-MS) revealed increased levels of 4-hydroxybutyrate (GHB) in 3 patients. SSADH deficiency was definitely diagnosed based on the clinical manifestations and the results of urinary organic acid analysis in the 3 children. It was concluded that early urine organic acid analysis is essential for children presenting with mental retardation, neuropsychiatric disturbance or epilepsy of unknown etiology.
Amino Acid Metabolism, Inborn Errors ; diagnosis ; therapy ; Developmental Disabilities ; Diagnosis, Differential ; Female ; Humans ; Infant ; Succinate-Semialdehyde Dehydrogenase ; deficiency

Insulin-like growth factors (IGF) system plays an important role in regulating growth and development of children. The change of this system is closely related to growth restriction caused by various diseases. This article reviews the research progress on how IGF system affects growth.
Developmental Disabilities ; metabolism ; physiopathology ; Humans ; Somatomedins ; metabolism ; physiology