Microcephaly

Abstract

This paper describes about the condition “microcephaly,” it tells about the condition, its causes, its presentation, symptoms, diagnostic criteria, treatment and the methods to support these affected persons. This paper describes about the causative factors and that are involved in this disorder.

Microcephaly

Introduction

Microcephaly is a disorder in which the baby's head is smaller than normal at birth. "Micro" refers to small and "cephaly" means head. Children with microcephaly have a small size brain and have mental retardation. Microcephaly is caused by effects of toxic substances during the fetal growth, or it is associated with genetic mutations that run in families. These factors put a fetus to risk, that impairs the development of the brain during pregnancy. There are many causes of this disorder which can be congenital or acquired.The important causes of microcephaly are craniosynostosis(premature fusing of sutures), chromosomal abnormalities (Down syndrome), cerebral anoxia, congenital infections, (cytomegalovirus, rubella, and varicella), severe malnutrition and uncontrolled phenylketonuria (Berger, 2009).

Discussion

It is a neurodevelopmental disorder in which the head circumference is 2 SD smaller than average. Microcephaly is mostly congenital or develops during early years of life. The disorder may be caused by abnormal growth of the brain, or associated with chromosomal abnormalities. Gene mutations of the microcephalin genes are associated with primary microcephaly. The life expectancy these affected persons is reduced and the prognosis is poor. Microcephaly mostly occurs in association with other diseases. It is associated with autosomal recessive, or sometimmes autosomal dominant gene. Acquired microcephaly occurs in postnatal period due to brain injuries such as cerebral anoxia or infection. Autosomal recessive and dominant are two genetic patterns in which these genes are transferred in a family. If the parents have one baby with autosomal recessive type of microcephaly, there is a 20-25 percent chance of another child with same condition (Bond, Scott, Hamshire, & Abramowicz, 2003).

Causes of Microcephaly

Hypoxic-ischemic encephalopathy

Cerebral vascular accidents

Teratogens

Intrauterine infections

Alcohol

Radiation

Uncontrolled maternal diabetes

Hydantoin

Maternal PKU

Autosomal dominant microcephaly

Autosomal recessive microcephaly

Syndromic examples

X-linked microcephaly

Chromosome Abnormalities

Trisomy 21

Trisomy 13

Trisomy 18

Gene Deletion Syndromes

7q11.23 deletion syndrome

4p deletion syndrome

Lymphedema, chorioretinopathy

17p13.3 deletion syndrome

Cornelia de Lange syndrome

Holoprosencephaly

Feingold syndrome

Smith-Lemli-Opitz syndrome (Cox, Jackson, Bond, &Woods, 2006).

Presentation of Microcephaly

Affected infants have neurological defects and develop seizures. Impaired brain development is common, disturbances of motor functions appear late in life.

These infants are born with reduced head size. The head stops growing, but the face continues to grow at a normal rate, which produces small head and a large face. The rest of the body is also underweight or dwarfed. Motor functions and speech development may be delayed. Mental retardation and hyperactivity are common. Seizures and spastic quadriplegia may also occur (Woods, Bond, & Enard, 2005).

Symptoms Of Microcephaly

Small baby's head

Poor feeding

High-pitched cry

Spasticity

Developmental delays

Mental retardation

Seizures (Jackson, Eastwood, Bell, 2002).

Microcephaly Diagnosis

Microcephaly can be diagnosed in prenatal period by ultrasound, which uses high-frequency ultrasounic sound waves to create images of tissues, and organs. Ultrasounds are used to view organs' function, and to see blood flow through vessels. Microcephaly may not be seen by ultrasound until the last trimester. The physician can diagnose the case of microcephaly by obtaining a ...