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Methylmalonic acidemia with homocystinuria, type cblJ(MAHCJ)

MedGen UID:
766829
Concept ID:
C3553915
Disease or Syndrome
Synonyms: MAHCJ; METHYLMALONIC ACIDURIA AND HOMOCYSTINURIA, cblJ TYPE
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): ABCD4 (14q24.3)
 
Monarch Initiative: MONDO:0013925
OMIM®: 614857
Orphanet: ORPHA369955

Definition

Combined methylmalonic aciduria (MMA) and homocystinuria is a genetically heterogeneous metabolic disorder of cobalamin (cbl; vitamin B12) metabolism, which is essential for hematologic and neurologic function. Biochemically, the defect causes decreased levels of the coenzymes adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl), which results in decreased activity of the respective enzymes methylmalonyl-CoA mutase (MUT; 609058) and methyltetrahydrofolate:homocysteine methyltransferase, also known as methionine synthase (MTR; 156570). The cblJ type is phenotypically and biochemically similar to the cblF type (MAHCF; 277380) (summary by Coelho et al., 2012). [from OMIM]

Additional description

From MedlinePlus Genetics
When methylmalonic acidemia with homocystinuria begins in adolescence or adulthood, it may change an affected person's behavior and personality; the person may become less social and may experience hallucinations, delirium, and psychosis. In addition, these individuals can begin to lose previously acquired mental and physical abilities, resulting in a decline in school or work performance, difficulty controlling movements, memory problems, speech difficulties, a decline in intellectual function (dementia), or an extreme lack of energy (lethargy). Some people with methylmalonic acidemia with homocystinuria whose signs and symptoms begin later in life develop a condition called subacute combined degeneration of the spinal cord, which leads to numbness and weakness in the lower limbs, difficulty walking, and frequent falls.

Some people with methylmalonic acidemia with homocystinuria develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The signs and symptoms of early-onset methylmalonic acidemia with homocystinuria worsen over time, and the condition can be life-threatening if it is not treated.

The signs and symptoms of methylmalonic acidemia with homocystinuria usually develop in infancy, although they can begin at any age. When the condition begins early in life, affected individuals typically grow more slowly than expected. This sign is sometimes iedentified before the baby is born. These infants can also have difficulty feeding and have an abnormally pale appearance (pallor). Eye abnormalities and neurological problems, including weak muscle tone (hypotonia) and seizures, are also common in people with methylmalonic acidemia with homocystinuria. Many infants and children with this condition have delayed development and intellectual disability, and some have an unusually small head size (microcephaly). 

Methylmalonic acidemia with homocystinuria is a disorder in which the body is unable to correctly process certain protein building blocks (amino acids), fat building blocks (fatty acids), and  cholesterol. The body is also unable to convert the amino acid homocysteine to another amino acid, methionine. Individuals with this disorder have a combination of features from two separate conditions, methylmalonic acidemia and homocystinuria. There are several forms of this combined condition, and the different forms have different genetic causes and signs and symptoms. The most common and best understood form, called cblC type (or cobalamin C disease), occurs in about 80 percent of affected individuals.   https://medlineplus.gov/genetics/condition/methylmalonic-acidemia-with-homocystinuria

Clinical features

From HPO
Cryptorchidism
MedGen UID:
8192
Concept ID:
C0010417
Congenital Abnormality
Cryptorchidism, or failure of testicular descent, is a common human congenital abnormality with a multifactorial etiology that likely reflects the involvement of endocrine, environmental, and hereditary factors. Cryptorchidism can result in infertility and increases risk for testicular tumors. Testicular descent from abdomen to scrotum occurs in 2 distinct phases: the transabdominal phase and the inguinoscrotal phase (summary by Gorlov et al., 2002).
Homocystinuria
MedGen UID:
42485
Concept ID:
C0019880
Disease or Syndrome
Homocystinuria is an inherited disorder in which the body is unable to process certain building blocks of proteins (amino acids) properly. \n\nThe most common form of homocystinuria, called classic homocystinuria, is characterized by tall stature, nearsightedness (myopia), dislocation of the lens at the front of the eye, a higher risk of blood clotting disorders, and brittle bones that are prone to fracture (osteoporosis) or other skeletal abnormalities. Some affected individuals also have developmental delay and learning problems.\n\nLess common forms of homocystinuria can cause intellectual disability, slower growth and weight gain (failure to thrive), seizures, and problems with movement. They can also cause and a blood disorder called megaloblastic anemia, which occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic).\n\nThe signs and symptoms of homocystinuria typically develop during childhood, although some mildly affected people may not show signs and symptoms until adulthood.
Methylmalonic aciduria
MedGen UID:
343266
Concept ID:
C1855119
Disease or Syndrome
Increased concentration of methylmalonic acid in the urine.
Coarctation of aorta
MedGen UID:
1617
Concept ID:
C0003492
Congenital Abnormality
Coarctation of the aorta is a narrowing or constriction of a segment of the aorta.
Patent ductus arteriosus
MedGen UID:
4415
Concept ID:
C0013274
Congenital Abnormality
In utero, the ductus arteriosus (DA) serves to divert ventricular output away from the lungs and toward the placenta by connecting the main pulmonary artery to the descending aorta. A patent ductus arteriosus (PDA) in the first 3 days of life is a physiologic shunt in healthy term and preterm newborn infants, and normally is substantially closed within about 24 hours after bith and completely closed after about three weeks. Failure of physiologcal closure is referred to a persistent or patent ductus arteriosus (PDA). Depending on the degree of left-to-right shunting, PDA can have clinical consequences.
Atrial septal defect
MedGen UID:
6753
Concept ID:
C0018817
Congenital Abnormality
Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum.
Pulmonary arterial hypertension
MedGen UID:
425404
Concept ID:
C2973725
Disease or Syndrome
Pulmonary hypertension is defined mean pulmonary artery pressure of 25mmHg or more and pulmonary capillary wedge pressure of 15mmHg or less when measured by right heart catheterisation at rest and in a supine position.
Growth delay
MedGen UID:
99124
Concept ID:
C0456070
Pathologic Function
A deficiency or slowing down of growth pre- and postnatally.
Failure to thrive
MedGen UID:
746019
Concept ID:
C2315100
Disease or Syndrome
Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.
Feeding difficulties
MedGen UID:
65429
Concept ID:
C0232466
Finding
Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.
Gastroesophageal reflux
MedGen UID:
1368658
Concept ID:
C4317146
Finding
A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.
Lethargy
MedGen UID:
7310
Concept ID:
C0023380
Sign or Symptom
A state of disinterest, listlessness, and indifference, resulting in difficulty performing simple tasks or concentrating.
Abnormal posturing
MedGen UID:
66660
Concept ID:
C0231471
Finding
Involuntary flexion or extension of the arms and legs.
Cerebral atrophy
MedGen UID:
116012
Concept ID:
C0235946
Disease or Syndrome
Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Thrombocytopenia
MedGen UID:
52737
Concept ID:
C0040034
Disease or Syndrome
A reduction in the number of circulating thrombocytes.
Normochromic anemia
MedGen UID:
66731
Concept ID:
C0235983
Finding
Inguinal hernia
MedGen UID:
6817
Concept ID:
C0019294
Finding
Protrusion of the contents of the abdominal cavity through the inguinal canal.
Micrognathia
MedGen UID:
44428
Concept ID:
C0025990
Congenital Abnormality
Developmental hypoplasia of the mandible.
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Delayed skeletal maturation
MedGen UID:
108148
Concept ID:
C0541764
Finding
A decreased rate of skeletal maturation. Delayed skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body.
Bell-shaped thorax
MedGen UID:
351320
Concept ID:
C1865186
Finding
The rib cage has the shape of a wide mouthed bell. That is, the superior portion of the rib cage is constricted, followed by a convex region, and the inferior portion of the rib cage expands again to have a large diameter.
Horizontal ribs
MedGen UID:
812840
Concept ID:
C3806510
Finding
A horizontal (flat) conformation of the ribs, the long curved bones that form the rib cage and normally progressively oblique (slanted) from ribs 1 through 9, then less slanted through rib 12.
Tachypnea
MedGen UID:
66669
Concept ID:
C0231835
Finding
Very rapid breathing.
Neutropenia
MedGen UID:
163121
Concept ID:
C0853697
Finding
An abnormally low number of neutrophils in the peripheral blood.
Methylmalonic acidemia
MedGen UID:
120654
Concept ID:
C0268583
Disease or Syndrome
For this GeneReview, the term "isolated methylmalonic acidemia" refers to a group of inborn errors of metabolism associated with elevated methylmalonic acid (MMA) concentration in the blood and urine that result from the failure to isomerize (convert) methylmalonyl-coenzyme A (CoA) into succinyl-CoA during propionyl-CoA metabolism in the mitochondrial matrix, without hyperhomocysteinemia or homocystinuria, hypomethioninemia, or variations in other metabolites, such as malonic acid. Isolated MMA is caused by complete or partial deficiency of the enzyme methylmalonyl-CoA mutase (mut0 enzymatic subtype or mut– enzymatic subtype, respectively), a defect in the transport or synthesis of its cofactor, 5-deoxy-adenosyl-cobalamin (cblA, cblB, or cblD-MMA), or deficiency of the enzyme methylmalonyl-CoA epimerase. Prior to the advent of newborn screening, common phenotypes included: Infantile/non-B12-responsive form (mut0 enzymatic subtype, cblB), the most common phenotype, associated with infantile-onset lethargy, tachypnea, hypothermia, vomiting, and dehydration on initiation of protein-containing feeds. Without appropriate treatment, the infantile/non-B12-responsive phenotype could rapidly progress to coma due to hyperammonemic encephalopathy. Partially deficient or B12-responsive phenotypes (mut– enzymatic subtype, cblA, cblB [rare], cblD-MMA), in which symptoms occur in the first few months or years of life and are characterized by feeding problems, failure to thrive, hypotonia, and developmental delay marked by episodes of metabolic decompensation. Methylmalonyl-CoA epimerase deficiency, in which findings range from complete absence of symptoms to severe metabolic acidosis. Affected individuals can also develop ataxia, dysarthria, hypotonia, mild spastic paraparesis, and seizures. In those individuals diagnosed by newborn screening and treated from an early age, there appears to be decreased early mortality, less severe symptoms at diagnosis, favorable short-term neurodevelopmental outcome, and lower incidence of movement disorders and irreversible cerebral damage. However, secondary complications may still occur and can include intellectual disability, tubulointerstitial nephritis with progressive impairment of renal function, "metabolic stroke" (bilateral lacunar infarction of the basal ganglia during acute metabolic decompensation), pancreatitis, growth failure, functional immune impairment, bone marrow failure, optic nerve atrophy, arrhythmias and/or cardiomyopathy (dilated or hypertrophic), liver steatosis/fibrosis/cancer, and renal cancer.
Hypomethioninemia
MedGen UID:
336368
Concept ID:
C1848555
Finding
A decreased concentration of methionine in the blood.
Decreased circulating adenosylcobalamin concentration
MedGen UID:
336369
Concept ID:
C1848556
Finding
The concentration of adenosylcobalam in the blood circulation is below the lower limit of normal. Adenosylcobalamin is one of the active forms of vitamin B12.
Decreased methionine synthase activity
MedGen UID:
376395
Concept ID:
C1848580
Finding
A reduction in methionine synthase activity.
Hyperhomocystinemia
MedGen UID:
812677
Concept ID:
C3806347
Finding
An increased concentration of homocystine in the blood.
Decreased circulating methylcobalamin concentration
MedGen UID:
867371
Concept ID:
C4021736
Finding
The concentration of methylcobalamin in the blood circulation is below the lower limit of normal. Methylcobalamin is a form of vitamin B12.
Elevated circulating propionylcarnitine concentration
MedGen UID:
1778397
Concept ID:
C5539596
Finding
Increased concentration of propionylcarnitine in the blood circulation.
Fetal distress
MedGen UID:
5164
Concept ID:
C0015930
Pathologic Function
An intrauterine state characterized by suboptimal values in the fetal heart rate, oxygenation of fetal blood, or other parameters indicative of compromise of the fetus. Signs of fetal distress include repetitive variable decelerations, fetal tachycardia or bradycardia, late decelerations, or low biophysical profile.
Wide intermamillary distance
MedGen UID:
473489
Concept ID:
C1827524
Finding
A larger than usual distance between the left and right nipple.
Hypertelorism
MedGen UID:
9373
Concept ID:
C0020534
Finding
Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).

Term Hierarchy

Follow this link to review classifications for Methylmalonic acidemia with homocystinuria, type cblJ in Orphanet.

Recent clinical studies

Etiology

Hwang N, Jang JH, Cho EH, Choi R, Choi SJ, Park HD
Mol Genet Genomic Med 2021 Nov;9(11):e1838. Epub 2021 Oct 16 doi: 10.1002/mgg3.1838. PMID: 34655177Free PMC Article

Diagnosis

Hwang N, Jang JH, Cho EH, Choi R, Choi SJ, Park HD
Mol Genet Genomic Med 2021 Nov;9(11):e1838. Epub 2021 Oct 16 doi: 10.1002/mgg3.1838. PMID: 34655177Free PMC Article

Supplemental Content

Table of contents

    Clinical resources

    Practice guidelines

    Curated

    • ACMG ACT, 2022
      American College of Medical Genetics and Genomics, Newborn Screening ACT Sheet, Elevated C3 Acylcarnitine, Propionic Acidemia (PA) and Methylmalonic Acidemia (MMA), 2022
    • ACMG Algorithm, 2022
      American College of Medical Genetics and Genomics, Algorithm, Propionic and Methylmalonic Acidemia: C3 Elevated, 2022

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