Achondroplasia, Neurofibromatosis, Apert’s syndrome and Marfan’s syndrome are the congenital chromosomal abnormalities related to increased paternal age.
Achondroplasia, Neurofibromatosis, Aport’s syndrome and Marfan’s syndrome are the congenital chromosomal abnormalities related to increased paternal age.
It is a genetic connective tissue disease in which individuals tend to have large limbs and fingers. Heart valve defects and aortic abnormalities are also commonly seen in these patients.
In this disorder there are multiple benign nerve tissue tumors which compress the nerves and cause various symptoms. There may be small mobile masses under the skin, cafe au lait spots due to impaired function of melanocytes.
Alports syndrome is a congenital neuropathy associated with advanced paternal age ( >35 years). Patients kidney problems along with occular (eye) and auditory (hearing) lesions often presenting with blood in urine and deafness.
New mutation due to advanced paternal age : in 75% cases
Old mutation transmitted from one or both parents : in 25 % cases
The cause of this abnormality is a mutant change in FGFR3 (Fibroblast growth factor receptor 3) leading to abnormal cartilage formation. Children with Achondroplasia have a retarded bone growth in their limbs with normal sized head and trunk. Specific features of achondroplasia are:
1-Short stature (dwarfism)
2-Average adult height 51.5inches (males) and 48.4 inches (females)
3- Short limbs
Under such circumstances where both the parents have achondroplasia, their offspring recieves a mutant gene from both the parents. Such a child is very unlikely to survive beyond a few month after birth.
Down’s syndrome related is to advanced maternal age. You can read more about this syndrome on :