The specific problems produced differ according to the particular abnormal synthesis involved. Common manifestations include ataxia; seizures; retinopathy; liver fibrosis; coagulopathies; failure to thrive; dysmorphic features ("e.g.," inverted nipples and subcutaneous fat pads; and strabismus. If an MRI is obtained, cerebellar atrophy and hypoplasia is a common finding.

Ocular abnormalities of CDG-Ia include: myopia, infantile esotropia, delayed visual maturation, low vision, optic disc pallor, and reduced rod function on electroretinography.

Three subtypes of CDG I (a,b,d) can cause congenital hyperinsulinism with hyperinsulinemic hypoglycemia in infancy.

Mutations in several genes have been associated with the traditional clinical syndromes, termed muscular dystrophy-dystroglycanopathies (MDDG). A new nomenclature based on clinical severity and genetic cause was recently proposed by OMIM. The severity classifications are A (severe), B (intermediate), and C (mild). The subtypes are numbered one to six according to the genetic cause, in the following order: (1) POMT1, (2) POMT2, (3) POMGNT1, (4) FKTN, (5) FKRP, and (6) LARGE.

Most common severe types include:

Symptoms of congenital Type III Galactosemia are apparent from birth, but vary in severity depending on whether the peripheral or generalized disease form is present. Symptoms may include:

- Infantile jaundice

- Infantile hypotonia

- Dysmorphic features

- Sensorineural hearing loss

- Impaired growth

- Cognitive deficiencies

- Depletion of cerebellar Purkinje cells

- Ovarian failure (POI) and hypertrophic hypergonadism

- Liver failure

- Renal failure

- Splenomegaly

- Cataracts

Studies of Type III galactosemia symptoms are mostly descriptive, and precise pathogenic mechanisms remain unknown. This is largely due to a lack of functional animal models of classic galactosemia. The recent development of a "Drosophila melanogaster" GALE mutant exhibiting galactosemic symptoms may yield a promising future animal model.

Children with Maroteaux–Lamy syndrome usually have normal intellectual development but share many of the physical symptoms found in Hurler syndrome. Caused by the deficient enzyme N-acetylgalactosamine 4-sulfatase, Maroteaux–Lamy syndrome has a variable spectrum of severe symptoms. Neurological complications include clouded corneas, deafness, thickening of the dura (the membrane that surrounds and protects the brain and spinal cord), and pain caused by compressed or traumatized nerves and nerve roots.

Signs are revealed early in the affected child's life, with one of the first symptoms often being a significantly prolonged age of learning how to walk. By age 10 children have developed a shortened trunk, crouched stance, and restricted joint movement. In more severe cases, children also develop a protruding abdomen and forward-curving spine. Skeletal changes (particularly in the pelvic region) are progressive and limit movement. Many children also have umbilical hernia or inguinal hernias. Nearly all children have some form of heart disease, usually involving valve dysfunction.

An enzyme replacement therapy, galsulfase (Naglazyme), was tested on patients with Maroteaux–Lamy syndrome and was successful in that it improved growth and joint movement. An experiment was then carried out to see whether an injection of the missing enzyme into the hips would help the range of motion and pain. At a cost of $365,000 a year, Naglazyme is one of the world's most expensive drugs.

Griscelli syndrome is a rare autosomal recessive disorder characterized by albinism (hypopigmentation) with immunodeficiency, that usually causes death by early childhood.

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder which manifests with insulin resistance, absence of subcutaneous fat and muscular hypertrophy. Homozygous or compound heterozygous mutations in four genes are associated with the four subtypes of CGL. The condition appears in early childhood with accelerated linear growth, quick aging of bones, and a large appetite. As the child grows up, acanthosis nigricans (hyperpigmentation and thickening of skin) will begin to present itself throughout the body – mainly in the neck, trunk, and groin. The disorder also has characteristic features like hepatomegaly or an enlarged liver which arises from fatty liver and may lead to cirrhosis, muscle hypertrophy, lack of adipose tissue, splenomegaly, hirsutism (excessive hairiness) and hypertriglyceridemia. Fatty liver and muscle hypertrophy arise from the fact that lipids are instead stored in these areas; whereas in a healthy individual, lipids are distributed more uniformly throughout the body subcutaneously. The absence of adipose tissue where they normally occur causes the body to store fat in the remaining areas. Common cardiovascular problems related to this syndrome are cardiac hypertrophy and arterial hypertension (high blood pressure). This disorder can also cause metabolic syndrome. Most with the disorder also have a prominent umbilicus or umbilical hernia. Commonly, patients will also have acromegaly with enlargement of the hands, feet, and jaw. After puberty, additional symptoms can develop. In women, clitoromegaly and polycystic ovary syndrome can develop. This impairs fertility for women, and only a few documented cases of successful pregnancies in women with CGL exist. However, the fertility of men with the disorder is unaffected.

Griscelli syndrome is defined by the characteristic hypopigmentation, with frequent pyogenic infection, enlargement of the liver and spleen, a low blood neutrophil level, low blood platelet level, and immunodeficiency. Very often there is also impaired natural killer cell activity, absent delayed-type hypersensitivity and a poor cell proliferation response to antigenic challenge. This may be caused by the loss of three different genes, each of which has different additional effects, resulting in three types of syndrome. Its inheritance is autosomal recessive.

Examination of the hair in this syndrome may be useful. Under light microscopy, these hairs exhibit bigger and irregular melanin granules, distributed mainly near the medulla. Under polarized light microscopy, the hairs appear monotonously white.

The syndrome causes cerebellar ataxia (balance and coordination problems), mental retardation, congenital cataracts in early childhood, muscle weakness, inability to chew food, thin brittle fingernails, and sparse hair.

Small stature, mild to severe mental retardation and dysarthria (slow, imprecise speech) are usually present.

Various skeletal abnormalities (e.g., curvature of the spine) and hypergonadotropic hypogonadism often occur.

Muscle weakness is progressive, but life expectancy is near normal.

There are three main types of the disease each with its own distinctive symptoms.

Type I infantile form, infants will develop normally until about a year old. At this time, the affected infant will begin to lose previously acquired skills involving the coordination of physical and mental behaviors. Additional neurological and neuromuscular symptoms such as diminished muscle tone, weakness, involuntary rapid eye movements, vision loss, and seizures may become present. With time, the symptoms worsen and children affected with this disorder will experience a decreased ability to move certain muscles due to muscle rigidity. The ability to respond to external stimuli will also decrease. Other symptoms include neuroaxonal dystrophy from birth, discoloration of skin, Telangiectasia or widening of blood vessels.

Type II adult form, symptoms are milder and may not appear until the individual is in his or her 30s. Angiokeratomas, an increased coarsening of facial features, and mild intellectual impairment are likely symptoms.

Type III is considered an intermediate disorder. Symptoms vary and can include to be more severe with seizures and mental retardation, or less severe with delayed speech, a mild autistic like presentation, and/or behavioral problems.

Peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions. This may be due to defects in single enzymes important for peroxisome function or in peroxins, proteins encoded by "PEX" genes that are critical for normal peroxisome assembly and biogenesis.

MPS VII, Sly syndrome, one of the least common forms of the mucopolysaccharidoses, is estimated to occur in fewer than one in 250,000 births. The disorder is caused by deficiency of the enzyme beta-glucuronidase. In its rarest form, Sly syndrome causes children to be born with hydrops fetalis, in which extreme amounts of fluid are retained in the body. Survival is usually a few months or less. Most children with Sly syndrome are less severely affected. Neurological symptoms may include mild to moderate intellectual disability by age 3, communicating hydrocephalus, nerve entrapment, corneal clouding, and some loss of peripheral and night vision. Other symptoms include short stature, some skeletal irregularities, joint stiffness and restricted movement, and umbilical and/or inguinal hernias. Some patients may have repeated bouts of pneumonia during their first years of life. Most children with Sly syndrome live into the teenage or young adult years.

The mucopolysaccharidoses share many clinical features but have varying degrees of severity. These features may not be apparent at birth but progress as storage of glycosaminoglycans affects bone, skeletal structure, connective tissues, and organs. Neurological complications may include damage to neurons (which send and receive signals throughout the body) as well as pain and impaired motor function. This results from compression of nerves or nerve roots in the spinal cord or in the peripheral nervous system, the part of the nervous system that connects the brain and spinal cord to sensory organs such as the eyes and to other organs, muscles, and tissues throughout the body.

Depending on the mucopolysaccharidosis subtype, affected individuals may have normal intellect or have cognitive impairments, may experience developmental delay, or may have severe behavioral problems. Many individuals have hearing loss, either conductive (in which pressure behind the eardrum causes fluid from the lining of the middle ear to build up and eventually congeal), neurosensory (in which tiny hair cells in the inner ear are damaged), or both. Communicating hydrocephalus—in which the normal reabsorption of cerebrospinal fluid is blocked and causes increased pressure inside the head—is common in some of the mucopolysaccharidoses. Surgically inserting a shunt into the brain can drain fluid. The eye's cornea often becomes cloudy from intracellular storage, and glaucoma and degeneration of the retina also may affect the patient's vision.

Physical symptoms generally include coarse or rough facial features (including a flat nasal bridge, thick lips, and enlarged mouth and tongue), short stature with disproportionately short trunk (dwarfism), dysplasia (abnormal bone size and/or shape) and other skeletal irregularities, thickened skin, enlarged organs such as liver (hepatomegaly) or spleen (splenomegaly), hernias, and excessive body hair growth. Short and often claw-like hands, progressive joint stiffness, and carpal tunnel syndrome can restrict hand mobility and function. Recurring respiratory infections are common, as are obstructive airway disease and obstructive sleep apnea. Many affected individuals also have heart disease, often involving enlarged or diseased heart valves.

Another lysosomal storage disease often confused with the mucopolysaccharidoses is mucolipidosis. In this disorder, excessive amounts of fatty materials known as lipids (another principal component of living cells) are stored, in addition to sugars. Persons with mucolipidosis may share some of the clinical features associated with the mucopolysaccharidoses (certain facial features, bony structure abnormalities, and damage to the brain), and increased amounts of the enzymes needed to break down the lipids are found in the blood.

The fifth type of hyper-IgM syndrome has been characterized in three patients from France and Japan. The symptoms are similar to hyper IgM syndrome type 2, but the AICDA gene is intact. These three patients instead had mutations in the catalytic domain of uracil-DNA glycosylase, an enzyme that removes uracil from DNA. In both type 2 and type 5 hyper-IgM syndromes, the patients are profoundly deficient in IgG and IgA because the B cells can't carry out the recombination steps necessary to class-switch.

Galactose epimerase deficiency, also known as GALE deficiency, Galactosemia III and UDP-galactose-4-epimerase deficiency, is a rare, autosomal recessive form of galactosemia associated with a deficiency of the enzyme "galactose epimerase".

Congenital dyserythropoietic anemia type II (CDA II), or hereditary erythroblastic multinuclearity with positive acidified serum lysis test (HEMPAS) is a rare genetic anemia in humans characterized by hereditary erythroblastic multinuclearity with positive acidified serum lysis test.

Congenital generalized lipodystrophy (also known as Berardinelli–Seip syndrome) is an extremely rare autosomal recessive skin condition, characterized by an extreme scarcity of fat in the subcutaneous tissues. It is a type of lipodystophy disorder where the magnitude of fat loss determines the severity of metabolic complications. Only 250 cases of the condition have been reported, and it is estimated that it occurs in 1 in 10 million people worldwide.

Mucolipidosis (ML) is a group of inherited metabolic disorders that affect the body's ability to carry out the normal turnover of various materials within cells.

When originally named, the mucolipidoses derived their name from the similarity in presentation to both mucopolysaccharidoses and sphingolipidoses. A biochemical understanding of these conditions has changed how they are classified. Although four conditions (I, II, III, and IV) have been labeled as mucolipidoses, type I (sialidosis) is now classified as a glycoproteinosis, and type IV (Mucolipidosis type IV) is now classified as a gangliosidosis.

The anemia associated with CDA type II can range from mild to severe, and most affected individuals have jaundice, hepatosplenomegaly, and the formation of hard deposits in the gallbladder called bilirubin gallstones. This form of the disorder is usually diagnosed in adolescence or early adulthood. An abnormal buildup of iron typically occurs after age 20, leading to complications including heart disease, diabetes, and cirrhosis.

This syndrome is characterised by typical facial appearance, slight build, thin and translucent skin, severely adducted thumbs, arachnodactyly, club feet, joint instability, facial clefting and bleeding disorders, as well as heart, kidney or intestinal defects. Severe psychomotor and developmental delay and decreased muscle tone may also be present during infancy. Cognitive development during childhood is normal.

Maroteaux–Lamy syndrome (also known as mucopolysaccharidosis type VI, MPS VI, or polydystrophic dwarfism) is a form of mucopolysaccharidosis caused by a deficiency in arylsulfatase B (ARSB). It is named after Pierre Maroteaux (1926–) and his mentor Maurice Emil Joseph Lamy (1895–1975), both French physicians.

Trichothiodystrophy (TTD) is an autosomal recessive inherited disorder characterised by brittle hair and intellectual impairment. The word breaks down into "tricho" – "hair", "thio" – "sulphur", and "dystrophy" – "wasting away" or literally "bad nourishment". TTD is associated with a range of symptoms connected with organs of the ectoderm and neuroectoderm. TTD may be subclassified into four syndromes: Approximately half of all patients with trichothiodystrophy have photosensitivity, which divides the classification into syndromes with or without photosensitivity; BIDS and PBIDS, and IBIDS and PIBIDS. Modern covering usage is TTD-P (photosensitive), and TTD.

Marinesco–Sjögren syndrome (MSS), sometimes spelled Marinescu–Sjögren syndrome, is a rare autosomal recessive disorder.

The diagnosis of ML is based on clinical symptoms, a complete medical history, and certain laboratory tests.

Schindler disease, also known as Kanzaki disease and alpha-N-acetylgalactosaminidase deficiency is a rare disease found in humans. This lysosomal storage disorder is caused by a deficiency in the enzyme alpha-NAGA (alpha-N-acetylgalactosaminidase), attributable to mutations in the NAGA gene on chromosome 22, which leads to excessive lysosomal accumulation of glycoproteins. A deficiency of the alpha-NAGA enzyme leads to an accumulation of glycosphingolipids throughout the body. This accumulation of sugars gives rise to the clinical features associated with this disorder. Schindler disease is an autosomal recessive disorder, meaning that one must inherit an abnormal allele from both parents in order to have the disease.

This syndrome is associated with microcephaly, arthrogryposis and cleft palate and various craniofacial, respiratory, neurological and limb abnormalities, including bone and joint defects of the upper limbs, adducted thumbs, camptodactyly and talipes equinovarus or calcaneovalgus. It is characterized by craniosynostosis, and myopathy in association with congenital generalized hypertrichosis.

Patients with the disease are considered intellectually disabled. Most die in childhood. Patients often suffer from respiratory difficulties such as pneumonia, and from seizures due to dysmyelination in the brain's white matter. It has been hypothesized that the Moro reflex (startle reflex in infants) may be a tool in detecting the congenital clapsed thumb early in infancy. The thumb normally extends as a result of this reflex.