Niemann Pick Type “A” and “B”

The type “A” and “B” are both caused by the same lack enzymatic activity and there is a growing consensus that the two forms represent opposite ends of a continuum. People with type “A” generally have little or no production of asthma (less than 1% of normal), while those with type “B” have about 10% of normal level of ASM.

While both type “A” that the “B” have an ASM which is significantly lower than normal, the clinical prognosis for these two groups of patients is very different. The type “A” of the NPD is a severe neurological disease that leads to death between 2 and 4 years of age. By contrast, patients with type “B” generally have little or no neurological involvement and may survive into late childhood or adulthood.

Niemann Pick type “C”

There are considerable variations in either the first symptoms of Pick’s disease type “C”, both in the progression of the disease. Symptoms may appear either early as a few months both in adulthood. Vertical gaze paralysis (inability to move the eyes up and down), enlarged liver, enlarged spleen, or jaundice in children are strong indications that the NPC should be taken into account. It is common that only one or two symptoms of Pick’s disease appear early in the disease.

It is believed that the number of people affected is higher, but it is often difficult to be diagnosed correctly. The NPD type “C” was initially diagnosed as a disability ‘learning, a slight delay, “a confusion” and delay the development of motor skills. Is not uncommon for a family to spend several years seeking a diagnosis, before the type “C” is identified. The type “C” is always fatal. The majority of children die before the age of 20 years (and many before the age of 10). The delayed onset of symptoms can lead to longer durations, but is extremely rare that anyone reaches the age of 40.

Other forms

In the past, other types of NPD have been identified. The older forms include:

The NPD Type “D” has been described in the French Canadian population of the county of Yarmouth, Nova Scotia. The genealogical evidence indicates that Joseph Muise (c. 1679 to 1729) and Marie Amirault (1684 – c. 1735) are common ancestors to all cases of Nova Scotia. This is now recognized as a variation of the type “C”.

The NPD Type “E” has been described for cases initiated in adults. E ‘considered a variation of the type “C” in which metabolic processes are only partially compromised by the delay in symptoms and slow progression.

Niemann Pick disease is transmitted autosomal recessive, which means that both parents were heterozygous-had one gene mutation present (but clinically healthy carriers of the mutation) and one in four children (25%) – heterozygous-will “inherit” the mutation genes from both parents and will become a patient. The gene that encodes the synthesis is located at chromosome 11p. There have been identified 12 mutations that can cause Niemann-Pick disease type A and type B.

Niemann Pick disease symptoms – The Niemann Pick disease symptoms are varied and differ depending on the type of the disease. There are described four types of Niemann-Pick disease, of which only type A and B are determined by scarcity (types C and D are determined by abnormal transport of cholesterol to brain cells, with accumulation of cholesterol in lysosomes).

Type A Niemann-Pick disease is the most common (almost 80% of cases) and is characterized by a normal aspect of the child at birth, possibly prolonged jaundice. By the age of 6 months there is evidence of hepatic and spleen enlargement and psychomotor retardation; neuropsychological deterioration is rapidly progressive. Manifestations of this disease are:

Eye: “cherry-red spot” in 50% of patients; Respiratory: – recurrent respiratory infections; Lung: diffuse reticular and fine nodular infiltrate; Abdominal: the increase in volume of the abdomen; Liver: hepatomegaly, jaundice neonatal; Spleen: spleen enlargement; Gastrointestinal: vomiting, constipation, difficulty eating; Skeletal disorders: osteoporosis; Neurological: Central nervous system: hypotonia, hyporeflexia, psychomotor retardation; stiffness; Blood: – anemia; “Niemann-Pick cells” in bone marrow biopsy;

Type B Niemann-Pick disease can begin during the infant or child in a routine consultation, the spleen-hepatomegaly, which is progressive and leads to increase in volume of the abdomen, in time, the associated impairment of the lung may be severe; around the age of 15-20 years is normal. Patients with type C Niemann-Pick disease have often prolonged jaundice (up to age 1-2 years) and progressive neuropsychological slow deterioration.

The spleen-hepatomegaly is less important compared with types A and B disease and survival is possible up to adult age. Specific diagnosis of Niemann-Pick disease is determining by the level of activity in leukocytes fibroblast cultures, which is very low (below 5%). In some countries this investigation is not yet available. In the absence of specific examination, histopathological examination of various tissues obtained by liver puncture biopsy= may bring evidence in favor of the diagnosis by revealing Niemann-Pick cell.

Niemann-Pick disease can be present in other diseases such as: Wolman disease, storage disease cholesterol esters or lipoprotein-lipase deficiency. Hematological evaluation can detect a decrease in the number of platelets, white cells and red blood cells. Ophthalmologic examination may reveal, for half of the patients’ red cherry spot. Analysis of mutations is possible in specialized laboratories (not yet available in some countries), specifying the mutation is useful for a patient to identify the carriers in their families at risk and prenatal diagnosis.